I feel pathetic...

Before I start, I would like to say that the details of my story might be controversial. I was not always the best person I could have been in certain situations. I'm not asking for judgement, Im merely asking for advice on how to look at the situation and help me move on from it. The story starts off with a girl I was dating at the time. After dating for nearly a month I had already been through enough drama and bullshit to amount to that of a 6 month relationship. Maybe a years worth. This girl (named amber) was more than I could handle. She was overly dramatic, self destructive, and ultimately unbalanced. She cleverly disguised this with a very cheery and fun loving personality upon initially meeting her. But over time she would slowly sync her bad qualities into the mix. Her demons and insecurity took over and it often seemed as if she was trying to sabotage our relationship because she hated herself so much. Around the time we had be together for a month, her younger sister came to visit. Her sister is named Jasmine. Jasmine and I were closer in age. Amber was 23 while we were both 20. Amber was already making assumptions that I would like her sister better than her before her sister even came here. Once I met and got to know her sister better, we became close and eventually hooked up behind my gfs back about a day or two before she had to leave. I was left happy, yet unsatisfied that we didnt get to have sex. As she turned down going that far because she felt bad...after that I left her with a kiss and that was the last I saw of her. She flew back to michigan which was a good 12 hours away from where im at. Although we were still friends, jasmine lost all interest in keeping in touch. It was clearly a fling, as she started dating some dude she had already been talking to before she visited. I was disappointed, but brushed it off and continued to do my own thing. Fast forward 4 months later. Its july, im curretly single. I get a facebook message from jasmine. She immediately confesses that she has missed me and wants to see me again. she also confirms that shes taking a break from her bf. a classic move for a girl to rebound directly to the next guy of interest as a backup. I knew exactly what it was, but i played along because i am insanely attracted to her. We kept in touch here and there. She would be on and off with her bf and that would constitute how much she would talk to me. I didnt let it bother me too much. I know how she is, and that shes immature. i knew she was too destructive to make it last with that dude. and when their thing finally ended, she started hitting me up again. it was strange, because one minute she was talking to me romantically and stuff, but the next minute shed talk to me about her ex bf looking for a shoulder to cry on. she even tried to get me to fuck with him by texting his phone...i played it off and took no part in that. but it left me confused and annoyed. but it was what it was. and i kept an emotional detachment from her knowing that as long as there was a chance of us having sex, id be fine putting up with dumb things like that. I eventually found out that she was going to the army on december 30th and i made an offer to come visit her in michigan after she exclaimed how much she missed me. she expressed an exuberance that showed she was truly excited to see me. And i wanted more than anything to see her...just for a few days. Well...reality set in to say the least. I had run into issues that required time and money, and really ate up most of my pay check. and seeing jasmine within the next few months would cost a couple hundered at the very least. I was starting to grow frustrated and disappointed. I wanted to see her badly, but my money troubles said otherwise. and to make things worse (or better depending how you look at it) jasmine once again started to lose interest. what once was a girl who would hit me up randomly with pictures and text seemed to stop hitting me up all together. i tried texting her, and got responses, but she ultimately showed minimum interest in the conversation. It was surprisingly bumming me out worse than ever. I was constantly stressing over if its worth to even pursue this thing anymore. I realized that she had made no offers to help me visit, despite her expressing how much she wanted me too. This was a clear game of "you're welcome to hit this, but you gotta do the work for it". and what seemed to be worth it was clearly tipping the other way, especially if i wasnt sure if jasmine even gave a shit about seeing me or not. And what makes me feel so pathetic is...id never go through this for any other girl. but jasmine...ive never lusted for a girl as much as i have for her. im incredibly attracted to her to the point where seeing pics of her makes me go nuts. being able to hook up with her was one of the best intimate moments ive ever had with a female. everything from her body to her face is amazing in my eyes. and when im physically near her, i enjoy her personality. but its clear that shes a very selfish and immature female. and she doesnt deserve a friend like myself. she really doesnt seem to care about me when it comes down to it...but for some reason i cant get her out of my head. this raw attraction i feel keeps her on my mind. and i feel dumb cuz there is not point to feeling this way. but i secretly hope and wish things would work out to where id be able to see her. i think that reality is about down for the count...and ive learned to accept that. but it still hurts and kind of sucks.So the question id like answered is... why do i feel this way if i clearly know shes not right for me? if i clearly know shes not a good person?

its lust and she has a control over you even when she is not right for you,you either waste time over her or you move on and end this.

It is understandable that you would have those feelings. Men inherantly are visual. Our attraction is instantly made with our eyes when we see what we like even if we know we can't have. It was like biting the forbidden fruit since you initially were seeing the older sister. The fire of that passion while still burning will eventually be reduced to a dull flicker. You are young and will soon kindle the fire with a new flame. Go about your daily life without looking to hard and love will find it's way to you. Best of luck!