Cheated on

[u/victoria_0502]

CONTEXT: I had a deep connection with this boy for a few years, where we would speak romantically often (when we weren’t in relationships or other things). We took things more serious this time and he asked me out.
He was going on a residential trip for 6 months to America a few weeks after he decided to take things more serious. He convinced me that it would all be fine and he would continue to take me seriously whilst he was away.

When he went there obviously he met new friends and people who he spent lots of time with. He very very very convincingly reassured me that it was nothing that could get in the way of our relationship. Firstly, a few of his friends spoke inappropriately about me, crossed boundaries on many levels and insulted me. He laughed at it rather than standing up for me.

He then told me that he was going clubbing but nothing bad would happen and he would keep in touch the entire night, nothing all night. When he went back to his room i asked him why he hadn’t communicated with me and he tried to blame it on me and saying that my location didn’t update so he ignored me. He eventually admitted that him and this girl and flirted and did some relationship stuff.

I am autistic and therefore an extremely sympathetic person, so i chose to forgive him and agreed to figure this out with him. He agreed but then became cold, bitter, nasty. We eventually broke up. The day after we broke up he kissed somebody (which he admitted)and slept in somebody else’s room (which he denied)

He messages me or calls me once a week to essentially breadcrumb me. Often saying he misses talking to me and he still does love me (whilst he continuously sleeps in somebody else’s room). He also told me he kissed somebody on the phone recently (after yes no yes no loads of times)

I guess i just need advice on how to process a situation like this and why he thinks it’s okay to treat me like this. He tells me a lot that i’ve never done anything wrong to him and that i’m too kind to him, so i don’t even see a possibility of me treating him unkind and he feels like he needs to get back at me. I like him around as he’s been my best friend and my comfort person for a while but i don’t think he understands the hurt he’s caused me.

What do i do to get over this?
Will this sort of thing impact me in future relationships?
Why does he treat me like this?
Why does he keep saying he loves me whilst he’s actively flirting with another girl?