You're english is just fine, so don't worry about that. Besides I am sure your english is better than my...well, whatever language is your native tongue.
On a seperate note your are absolutely insane going back to him. He treated you in an atrocious manner, further he cheated on your often and over a long period of time. He also breaks his promises. Which means trust is never going to be a thing in this relationship. I also fear he is taking advantage of your nature to get what he wants, when he wants it.
I don't know if you have any family or friends you can lean on for support, I suspect probably not locally, but if you do please do lean on them for support. I would also be inclined to move further away, 10 minutes away is 10 minutes too close. Also, don't have him move in. Crazy thought I know, but I think you are entitled to meet someone who is trustworthy, loving and doesn't cheat. He isn't good for you, and you know it. Hence why it's all so upsetting for you. You've given him a chance, it didn't work out. Why put yourself through it again?
You need to get out of dodge, and pronto!