Most Helpful Girl
First off, I just have to point out that the fact that he basically pressured you to having sex with him is not cool. Yes, maybe it turned out to be OK or whatever, but still, he should have had enough respect for you to realize that he should have backed off and given you more time.
Now that that's out of the way. I think you questioning whether you should be with him or not is your answer. If you were perfectly content with the relationship, you wouldn't be questioning it. Granted, you can't always be perfectly content with everything, but this seems to have been going on for some time now. You even said yourself that you can't get over the past and forgive him. And, you know, if the both of you were happy together, you wouldn't have broken up 38475 times over the past year and a half...
Just break up with him and stick with that. I mean, he stole your brother's work, you've been on and off since you began dating, and you can't let go of the bad things he has done. I think those are all good reasons as to why it simply won't work out in the future. You just have to be determined. You can't take him back every single time you feel weak. Otherwise you'll just drag out the entire process, which is completely unnecessary.