I feel for you...you gave it your all, and that's ALL you can do.
Remember if you decide to go ahead with the breakup, make it final, and don't go back. That would be asking for more pain from someone who obviously has no problem dishing it out, even to someone he "loves". Be thankful you found out now, before you got married...many aren't so lucky. And though it may hurt now, it is better than being in a relationship that could end in divorce. Believe me, I know.
I agree with mtnndeww; don't live with someone...it is asking for trouble...breakups are harder and that isn't what dating is about. Dating should be about getting to know someone, not a halfway committment (which is how your boyfriend sees it even if you don't).
best wishes and God bless, my prayers are with you.