My boyfriend is starting to treat me like **** but maybe i was the cause, should i stay or leave?

My boyfriend and I are going to six months, but the problem is that he is starting to make me ask myself why we're even together. I admit at the beginning of the relationship, i would take advantage of him because i thought he was always gonna beg me and be all sweet. Sadly whenever we get in an arguement now, he acts like he doesn't care about my feelings and threatens to break up with me. I feel like i was such a ********* that he's already at his limit. Is it my fault, oh my gosh what do I do? *No i don't want to lose him.