I myself have been in his position before so I can speak from experience, by your actions when you were going out the last time it sounds like your relationship got too deep and the only way to cope was for him to take it out on you. To stop himself loving you he had to make himself hate you, imagine after you broke up he’d been making himself hate you for all those months. He was making himself hate you so that he wouldn’t be sorry that you broke up, even though deep down during the relationship before he cracked his heart had already been broken by you and the first cut on a heart hurts the most, I’m guessing as you were in high school you were each other first love and no body forgets that.
What I’m trying to say is that you’ll never be able to change him relationships change people, you learn from experiences, for me I had to find someone else i truely trusted before i could let them in my life and I’m guessing for him he will need to get out of his head all up the built hatred and you have to build and earn his trust because that is what was lost from the last time you were together. Earning trust takes time so give him it, it’s going to be hard because you live so far apart and as much as you love him you have to be prepared in case things don’t work out. In my experience my ex who treated me badly cam back to me a year later and begged me to go back out with him, I wasnt sure how I felt about him I still loved him, but I did not trust him, I spent the whole time trying to convince myself I hated him so that I wouldnt love him. I told him it would take time before we could get back together properly because of trust, but when we finally got back together it was never the same, the relationship lasted a month before i called it off. I came to realise that we had both changed, grown up and were different people and although as much as I loved him I was not in love with him and that is something that was probably never going to change.
I don’t know your full situation but I hope you understand what I’ve written and it helps you to understand him in order to help him.
All the best
-Jen-