How do I get out of this mess ?

I am a 21 year old guy. I have never dated a girl and I think I'm really desperate right now. I have spent the last 5 years of my life chasing 3 girls ( one after the other ). I spoiled my chances with all of these girls by revealing my feelings in an early stage and then acting like a creep. I think I liked all these girls just for the looks. Currently I like another girl since the last 5 months. I haven't revealed my feelings yet. I became friends with her when we were assigned as a team for a college project. I got to know her well. Found many similarities with her and we would enjoy time together. She told me she likes a guy friend of her for the last 2 years and she hasn't been able to move on. Soon as we got close, she told me about problems in her life. I at that point had no feelings for her. I would help her out, I would type long as messages to make her feel good. I thought she appreciated it. I would listen to her problems for hours and used to motivate her. She would bitch about her friends and I would be there to listen and help her out. Then our project ended but we obviously remained friends. During the break, she would not talk much to me. She used to wait for a day to reply to a simple text and would act very mean. I told her a few times that she was being mean and how I felt. She would always say she is trying to improve and all that shit. Since we were good friends, I decided to do my final project with her which would last for 1.5 years. I thought of her a good partner and said no to all my other friends. I was of the opinion if I get to spend more time with her, she would eventually like me. Currently I see her everyday but we don't talk much. She doesn't have much problems in her life now ans so chooses to spend more time with her other friends having fun. She talks to me only about the project and when anything is bothering her. I still type long ass messages to comfort her and now days she doesn't even seem to appreciate my efforts. I still like her. Again I think I like her partly because of how hot I find her. I don't even have fun with her now days. But I still like her. I spend my entire day thinking about her, how we an have a future and what not. In reality there is no future because I am leaving my country after these 1.5 years. But I constantly spend time thinking about her. Today I got so mad at all this, i told her how I felt that she would only talk when she has some work. She simply denied it and in the end said she would try to not behave that way. I don't even know what that means. Frankly, I'm tired of doing all this. Being a support system for her. It sucks the energy out of my life and I am not able to do anything in life. I can't even study for my exams. All I do is day dreaming and keep thinking about being with her, having sex with her and what not. It's driving me crazy. I see her talking with other guys all day and go crazy jealous. I stalk her online and try to find out who she is talking to. I have done so much for her but she doesn't give 2 shits about me. She says she cares about me and some part of me believes that but she has never done anything like that to prove it. I think she acts mean without even realizing she is being mean. For some reason some part of me believes that she is a good fit for me. maybe because of the initial compatibility. I think I should move on from this but at the same time I still want to be with her someday. Also I don't know how to move on from someone. I have moved on previously from other girls only when I have liked some other girl. Since the last 5 years there hasn't been a singly day where I have not been in "love" with some girl. I keep jumping from one to another. I need someone to tell me from an outside perspective what to do. Sorry for making it this long. I think I am stuck inn this mess forever. Any help would be great.

There is nothing about this girl that indicates she'd be a good fit for you. And it's clear you aren't even that good of friends. You definitely need to move on. But not to another girl. You need to get comfortable with yourself, as an individual. You are not missing your other half. You won't find healthy love til you can be happy being on your own, without focusing on people that aren't right for you. Spend time developing your own interests, and you'll meet new people that share those interests. You'll be encouraged to pursue whatever make you happy, which is the best way to figure out what your priorities are. You shouldn't be making "friends" with the assumption that it will lead to a romantic relationship. If you make friends based on your own ulterior motives, then you're not being a very good friend. If you make friends for the right reasons, you won't resent them when they don't fall in love with you. Stop trying to manipulate people through "friendship", and work on being a better friend to the people in your life. If you can do that, you'll find you like yourself a lot more, and won't feel the need to focus on a girl that's not interested in you. Nobody owes you love. You have to earn it. A good start would be building honest friendships, without the assumption people should behave how you want them to. If someone behaves badly towards you, it is not your job to try and "correct" them. It is your job to set and enforce healthy boundaries for yourself. If you allow people to consistently mistreat you, that's on you. Befriending girls you find sexually attractive, then getting upset when it doesn't turn into something more, is not how you find love. It's how you alienate people and keep yourself the victim of your own manipulations. All of that said, you are still very young. There is plenty of time to find the RIGHT love, and not just some girl you think is hot. Try focusing on shared interests and values, and you'll find much healthier connections. Work on being a better, healthier person, and the right people will find and appreciate you. Work on being a real friend, and focus on your own growth. Put yourself around people that are good for you. You shouldn't need a girl to feel whole. And as long as you feel there's some void you need to fill with some random hot girl you befriend with shady intentions, you'll never be any happier than you are right now. And that would be as tragic as it is unnecessary.