My ex broke up with me, but says it's my fault. And now acts like he hates me. What's going on?

Anonymous
So I was with my boyfriend for a year and a half. And friends before that. We spend probably 75% of our free time together and usually are very happy. A few weeks ago I decided to make an effort to seeing my girl friends more often, since it'd been cut down to once or twice a week if that. He hasn't ever been one to drink with the boys but he decided to have a few friends over at our house for drinks and cards. I thought it was unusual for him but I supported him making friendships and whatnot. In the last week of our relationship he acted very moody and on edge. Picking fights randomly and just acting strange. And then I spent the night out of town as it was a friends birthday, and he told me he was going to have a couple friends of his over. I said fine just call me before you go to bed. Well during the day he was texting me and acting odd again, and he told me he's not sure what he wants. I was pretty surprised but I had known something was wrong because of his strange behavior. I'll be honest I freaked out a little, because I haven't done anything wrong and I've been quite accommodating and always honest. And the next day he tells me that I'm unsupportive and that I don't respect him and that it's over. I was a little sour with him when he started doubting his feelings and we both said some things we didn't mean. But he wants nothing to do with me and blames the failure of our relationship on me. What did I do? And why is he acting this way?
My ex broke up with me, but says it's my fault. And now acts like he hates me. What's going on?
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