Need help with this girl...

So I've been having issues with this girl for about 4 months now, and I've kind of reached the point where I don't know what to do, or where to go for advice. Hopefully someone here can help me. I am 18 years old, just graduated from high school. If it matters, the girl I'll be talking about is two years younger than me. And I'm sorry that this is very long, but I don't want to leave any details out. Thank you so much for taking your time to read this. I basically met this girl when trying to get over a bad break-up and other problems that led to me losing a lot of friends, or losing trust in the friends I had, as well as obviously my previous girlfriend. Life got really bad for me, but I just sort of sat with her at school one day and made friends with her and things started to quickly get better. But as time moved on, a few weeks or so, I began to develop feelings for her. I ended up just staying friends with her for a month or two, and trying to compliment her and be friendly with her when I could, but to be honest I was incredibly shy. I ended up getting her number after asking her one day and we began texting and we got along really well. However after about a week or so of texting I started to realize that I was becoming dependent on it (due to me being so shy) and that I was becoming less social with her in school, and it started to make me seem antisocial and maybe creepy. However, knowing her and how friendly she was, I felt like I could just get her alone and explain everything from my feelings for her and why I acted the way I did with texting her and she would understand. After trying to get her alone to tell her all these things (which didn't happen; due to bad circumstances, not just her not wanting to talk to me) I eventually just wrote her a four-page note telling her about what I thought about her (how I liked her a lot) and why, and how she made my life so much better, and I explained everything I've done and felt from the very first day. At the end of the note I made it clear that I just wanted her to do whatever made her happy. And I lived by that. A couple days went by and I was incredibly nervous, but she took her time and wrote back to my note. The note was filled with positive things about how she felt so loved by what I said, and how it just made her speechless (in a good way, she later clarified ;) ). She told me that we should definitely stay in touch and hang out after I graduate and she ended the note with her name followed by a heart. Reading that was the best thing in my life. That was on the last day of school, and I graduated pretty darn excited about her. The day after my graduation I found out from someone that she just started dating this other boy. I found it quite interesting after what she wrote, and it hurt me, but I was really happy for her that she did what made her happy and I was for her all the way. I continued texting her and I always stayed friendly. However I do admit that I always wanted to talk to her, so I often sent two or three messages at a time (maybe one or two a day) if she didn't respond until she did. I didn't notice any signs of that bothering her, and I actually asked her and she said that it didn't. I trusted that it really didn't. So through texting, since it was summer, we stayed in touch and we became much better friends (we began texting a lot more often too), sharing different things about each other and joking around and such. It never was flirting or anything, just being friendly. I asked her quite a few times to hang out, but she always made excuses and said she was busy. It was true that she was a really busy person, she has a lot of athletics going on among other things, but I still felt that maybe if she cared about me she'd try and find time. After some time, my feelings for her started to catch up to me and I didn't know how to feel since she never seemed interested in spending time with me. But then all of a sudden she did invite me to hang out. Since we both were really religious, and having shared with her a lot of problems I was having with friends and family and such, she invited me to come to her youth group to see what her church is about and such, where we all talk about things going on in our lives. Needless to say, I had a really fun time with her there, and it only made me like her more. Since then I've spent time with her once more, and it was pretty much the same thing. We went to an event for her church, and we had a lot of fun. But around this time was when I started noticing that her mood was changing a little, and when I asked her how her day was she would say that they weren't the best. This is where my problem starts. I asked her another day if that day was better for her, and I told her how I could come to her church youth group the next week, but she never told me how her day was, but instead discouraged me to come to her church that week because very few people would be there. I asked if we could hang out anyways, nothing. Texted her the next day something different, nothing. She just disappeared. I don't think I was acting desperate, I was just scared and I really cared about her, and I had no way of knowing whether or not she was okay. I guess I panicked a little. I often sent around two messages a day, and they were really long either about how I was scared about her or asking her where she was, or how much I missed her, or something along those lines. I started feeling depressed (I relied heavily on her to feel happy everyday) and I spent a lot of my time sleeping, since I had headaches all the time. I slept with my phone at full volume just in case she would contact me or if she needed me for something. It never happened, but I did it anyways. Slowly she started talking to me again saying that she was sorry for not talking to me, that she was having really bad headaches and didn't want to look at her phone, or that she was busy or things like that. I began to feel bad because I didn't want her to feel sorry, I just wanted to know if she was okay. I asked if it there was something I did and she said no, basically I just wanted to make sure that I wasn't blocking her somehow from being happy. From what I can tell, she broke up with her boyfriend (Facebook let me know I guess) and that's all I really know. So now some time has passed and I can't get ahold of her anymore. I miss her so much and I tell her that, but I always get really short replies or nothing at all. I guess at this point, I'm acting desperate and I'm trying not to, but life is just so hard without her there to make me smile all the time. I'm currently having issues in all other parts of my life and it's difficult to find optimism anywhere, and without her it's so much worse. We haven't had an actual conversation in almost two weeks now, and everything she texts to me is just a few words. And again, since it's summer and I've graduated, I don't see her in school on a regular basis anymore and I will not ever again. I'm not sure what to do. There's lots of traits I like about her that I didn't mention, and I really feel like I won't find someone this perfect for me ever again, so I'm currently not very open to the possibility of looking for another girl. And yes, I want her to like me and be my girlfriend, but if nothing else I just want her to be there for me as a friend to talk to. Her not being there is making me really depressed. I've asked all the friends I have (not all that many) and all of them don't really have advice for me. I've spent countless hours searching the Internet for various things that might help. I'm determined to fix this I guess. I'm at a loss, and I really really miss her and care about her and everything. What should I do? Thank you so much for your time.

You are relying on her too much. If she wanted a relationship with you she wouldn't disappear on you. You need to stop messaging her. Get out and find more people. She is living her life. You need to live yours.

So I guess the fact that I need to stop messaging her is clear, but I guess what isn't is whether or not I should still try and talk to her, face to face, if that's possible... In short, should I just stop messaging her or should I simply not talk to her ever again?

Stop messaging her. Give her one text per one text. Don't call her. If she calls you great. You can still hang out but only if she asks you to, don't self invite. You have too much invested in this person. Its not healthy. Only cut her off if the little bit of contact or her texting you causes you to slide deeper into the crush/obsession. Get involved in speaking and meeting others. There is a chat room on here btw. Its small and you can get to know every one easily. I would only cut off the girl if it was causing you more problems and you felt you couldn't handle the small contact with out wanting more.