<human>: Quick background: My 5 best friends of 8 years slowly axed me from the group. They started leaving me out of stuff secretly, then outright harassing me. Blahblah I felt crushed and depressed.

I reached out to my old friend from one of my chem classes. Turns out the same thing happened to him recently. We connected and supported each other.

One year later, I introduce him to my then-gf of 3 years. Eventually it was obvious he had feelings for her (sent her flowers and stuff, my then-gf gave him her address). She told me about the flowers and said she was grossed out that he was hitting on her.

Now, my then-gf was the sweetest, nicest, and as cliche as it is, innocent girl I've ever known. Not a partyer, drinker, smoker, none of that. Very sheltered go to school go home kind of girl. So, naturally I was just like "pft, ok, plenty of guys have hit on her and I trust her so this is whatever."

My friend goes off the grid though so I can't contact him. 

A week later she dumps me, gets with him the next week and they already start to have intercourse. (I know this because 2 weeks later she contacts me and starts begging for me to take her back)

**Help me.** It's not even rage anymore. I feel nothing but raw humiliation and it hurts to breathe. I feel like I was completely fooled by two people I totally trusted, and above all I feel ....*dominated*, I guess, by him. I feel like his bitch. I keep having thoughts of him fucking her and I can't control it. My self-confidence is zero and...I don't know, it's just an awful feeling. 

Anyone have encouraging words/advice?

Can you provide a brief overview of the text?
<bot>: Completely trusted my then-gf. Friend starts hitting on her and eventually succeeds in stealing her. I feel robbed, humiliated, and dominated. Please help me.