I am all new to this forum, but I am in big need for some help.
Around 2 years ago I meet that girl. In that time she were already in couple with a borderline guy treating her very bad. She is a typical codependent/love addicted girl, and relate to most of the behavours related to that. Superkind and always help everyone and constantly have people take advantage of her.
We become very close friends, and it was something more from the beginning. A very good connection. When she finally broke up, she wanted so badly get in couple with me, but she were scared of hurt her ex-boyfriend. So somehow she always had problem to fully commit to me, as she were still friend with her ex.
Time passed, and she always acted like a couple with me. Holdning hands, kissing and sleeping together. However no sex, even if we were close to make it many many times, but we had some other sexual things going on. She all the time told me she like me so much and care about me, but not yet ready for couple.
Around 6 months ago, she found out her ex has a new girlfriend. In that moment she finally felt less guilty for me. She started to kiss more, and act more sweet. However it was like always ups and downs. Sometimes she act amazing with me, and sometimes she is cold and act bad. Always apologizye for her changes.
4 months ago she meet a guy that she got involved in. Typical dominant needy type. She said she never liked him, but it was something that got her attracted to him. (he were a veteran of military and had several personal problems).
Nothing happened, even if she sleept over to him some time, the guy went away on a long trip, back to US (I live in europe).
Things went back to normal, and she more or less acted like a couple all the time. I was not ok, after this happened and have problems treat her like before, as I felt she ruin all.
She say she is so sorry for all. That the guy is manipulative and she was scared of almost get involved in something. And that it was good that he left.
Now I found out she is going to US for a work for 2 weeks, and apparently she is going to meet up with this guy again. But just as friends. She said he helped her out with find that work. Its her dream go to US, and I really understand she want. And I always told her she should follow her dream.
But after found out that the guy will probably host her, I have problems to be ok with all.
She said its nothing, just that she will go and come back. and that they are just friends now.
I treated her cold lately and want to see her less. Do I overreacting?
I just feel all the situation is messed up and its not only this. On one hand it feels like I have been used a lot in this situation. On the other side, I feel in love with her from the beginning and we usually have a great time together. I care about her a lot and I dont want to lose her. She speak sometimes about get together and marry, that I am a perfect guy for her. Just that time is wrong.
We also had planned to go to her home country and study medicine for a long time. All this would be a dream if we were just together. But not now, with all this unsecure things going on.
But anyone of you having similar situation. Advices please.... Shall I just stop be jelous and act like a man, or run far away from all this mess?

This take all my energy so far. I start do doubt myself and my own abilities lately. Please help!!