I really miss him..

Ni
My ex and I broke up about a week ago... I understand he was very controlling and abusive but I can't get it out of my head that maybe if I try to talk to him via letters he might give it another shot. I didn't do anything wrong, I told him where I was when I was there, when I left, didn't work at places he didn't want me to, wore clothes that he preferred I wear, made me stop being friends with certain people and all that. I do see that as too controlling.. he told my mom he blocked my number. The night we broke up, I was wearing a sweater and he started calling me a slut and saying how I'm trash.. I recorded part of it. The thing is, despite all those things, I really fucking love him and I'm willing to make it work. Truly I think I should give it a couple more weeks before trying because it's still new but he's already on dating sites.. it really hurts me. I'd do anything for that guy, anything. I've never loved like this before.. I feel so sick because of everything. I just need some helpful advice please... I said I'd write him letters because my friend said that would be better than contacting him on social media. We had a house together and a dog, and now I can't even see my dog.