I'm going to try to keep this as brief as I can.

I met this girl 2 years ago. I was 19 she was 18. We clicked INSTANTLY and made out the first night we met. We've since had a very long and great (for the most part) relationship. Back in August, she moved to a city 3 hours away for college. We both knew it was going to be challenging but after the amazing summer we had just spent (living together all summer at her sister's empty apartment) we both agreed to make long distance work.

The first month was still great. I went to see her every other weekend and she would get away for a few days here and there to see me. With time, we started to fight a lot. We always used to fight when we lived in the same city as well but when you can't be with each other in person due to the distance it takes a different kind of toll on you. Anyways, back in the middle of October when she came to visit me I saw that she had a 12 days streak on Snapchat with some guy who was her lab partner and one of her close new friends in her college class. She tells me I have nothing to worry about, I tell her I feel it's not okay. Once her project with this guy was done I asked her not to speak to him anymore and she agreed.

Anyways a week later, I logged onto her instagram to find she had sent him videos of cute birds (She always used to talk about wanting to own birds in the future once we got married etc) with a few hearts and live struck emojis. I flipped when I saw this but she said there was really no intention other than to say the birds were cute and wasn't trying to flirt with him. Beginning of November, following some more fighting and the longest we've gone without seeing each other, we decide (Mutually) to break up.

Since then I've tried to cut her off but honestly I am too weak too. I went about 10 days once without speaking to her but then whenever she's been in town (on 4 seperate ocassions) we've met up, made out, fucked, said we love each other etc. A month ago, she started flirting with tye guy I was getting jealous over. She was on holiday to visit her parents that live in another country during the christmas period so they day before she was leaving we met up and she told me things had started happening between her and that guy. It sucked to hear, but I understood our relationship was over and that at least she's not cheating on me (Which had happened once back in February.)

Anyways while she's away, I tell her I dont mind what she does and if she wants to be with this guy she can. She came back 2 days before New Years Eve (4 days ago) and we met, went out to dinner, fucked and then the next day I drove her to the train station and we left it (Pretty beautifully) there. We had agreed to be best friends (I am still very much in love with her) and when I called later that night at midnight to check if she got home safe, she picked up, told me very briefly she's with Adam (Let's call the guy that) at home and can't speak. It felt like such a slap in the face and needless to say it fucked me up.

What really has got me all sorts of fucked up right now was that she posted a picture of him and her eating at a restaurant last night during new years eve with a bunch of hearts in the caption on spanchat. She didn't block me from seeing it so obviously she knew I would. I had not realised whatever she had with this guy was moving this quicklu to the point where she would be posting him online and heading towards boyfriend girlfriend.

What I did was listen to the advice of my friends and cut her off once again but for this time for real. I wrote her a very long message saying how disappointed and heartbroken I was, and that I felt like instead of feeling the emptiness I feel of losing my best friend and girlfriend of almost 2 years, she's jumping into something new just to avoid feeling the same pain.

I haven't been able to stop thinking about her. I'm currently in between 2 jobs (I'm starting my new job in 2 weeks) so I have a loooot of time left over to spend my days thinking and obsessing over her and this new guy. I feel regretfull for not being able to keep the relationship working because the plan was for me to change schools and move in with her in January (So today basically) but we didn't quite get to the finish line.

Can anyone tell me what I can do to get over her? Should I attempt to stay best friends with her? How do I stop myself from having destructive thoughts? Also, this guy obviously doesn't realise that we were fucking just 3 days ago a few hours before she went back to her city and they slept over together, so is it worse for me or for him?

Any advice would be well appreciated. I don't even know if this is the right subreddit for this, if not, my apologies.