Am I ruining my mother’s relationship?

I’m seventeen and not the best daughter... I don’t do drugs, or consume alcohol or tobacco, I don’t party or stay out all night, but I misbehave in many other ways. I forget to do certain chores, I forget things my mother has told me, I don’t take proper care of the animals at times... you get the point.

My biological father left us when I was like nine... since then she’s had a verbally abusive(to her, indirectly to me) husband, and three boyfriends... one had a breakdown due to substance abuse we saw signs of but weren’t aware of until that.

She has a new boyfriend now, he’s amazing and we get along fine... but since I misbehave and he definitely isn’t as productive and giving as my mother, their relationship is crumbling.

Now every time they fight she comes to me and asks me if I’ve gotten what I wanted, since she’s convinced that I intentionally make her angry all the time, and I don’t let them have intimacy. (Note that they don’t go on dates and only leave the house for work.)

She says that with my behavior I’ve ruined all of her relationships. I don’t know how to manage this weight since each of her breakups hit me pretty hard, losing father figures and such. I feel like I’m worthless and a waste of space, like I destroy everything and I don’t know how to stop. Yesterday the same thing happened, He hasn’t left yet but she asked me:

“Are you happy? You’ve got what you wanted, my boyfriends going to leave because I’m angry all the time, and we can’t even be together because you’re always around. And you’re not doing this on purpose? Yeah and I’m stupid. Don’t worry, I’ll rise above it, I’ll get bigger. This relationship won’t make it, but I’ll find a way to deal with what you do.”

I cried the whole day. I don’t know how to live with this. If I’m really messing up the relationship how can I stop? How can I deal with this guilt and pain?