<human>: Can you provide a brief rundown of the text in within 3 sentences?

So I (f/18) have been dating a guy (m/18) for roughly 15 months now. However, for the past five or six months, he's been acting very aggressive and abusive when I'm upset about something. I won't lie -- I get upset about things pretty easily. However, he screams at me, insults me, and threatens me way more than I think I'm deserving. If we were arguing over the phone, he'd hang up and ignore every incoming call I try to make. However, after an hour of acting like this, he takes a breather and apologizes for how he was behaving. Each time, I take him back because I think he's just troubled and needs some guidance. However, it's getting to the point where I stay up until 6 AM trying to calm him down when I have to wake up at 7 AM for classes, or I stress myself out too much where I can't eat or sleep. He's tried therapy before, but it didn't change much. He has mother issues (she was very abusive, and she died back in 2005) and overall family issues. Would it be cruel of me to just opt out and leave him? I do believe I love him and some part of me THINKS he'll get better, but I'm not very sure anymore. The answer does seem pretty clear, but still, do you think it's worth it for me to stay?
<bot>: My boyfriend has recently been very abusive, but we've been dating for so long that it may not be worth breaking up. Thoughts?