What would you do? (long)

Hello,

I'm new here so I Don't really know how this all works but I want some advice please. (btw English isn't my first

language, sorry for any mistakes)

So. I'm with my bf for 4,5 years now. I love him so much, we have a house togheter and a cute cat.

But 2017 have been really hard for us. I got sick, Stayed in the hospital for some time, money was short and we couldn't afford anything at the time. it was really Stressfull.

We got into some fights. And we would just scream at eachother and hè would punch a wall or door and it made me scared, but also really angry, because hè knows I had to deal with a aggresive brother who would hit me all the time for years after my parents split up. But a few weeks back, hè didn't punched a door or wall but himself, really hard in the face. I tryed to stop him, but Hè was too strong, the next day his face was all blue!! :(

I also have this sickniss when I get too much stress my heart starts racing and I faint.

So when I screams at me, this happens from time to time.

I know he sound really bad right now, but hè can be really Sweet and caring. And he said 2017 made us stronger and it will be all good from now. I wanted to break up, because its not healthy but he begs me to stay and hè starts crying and won't let me leave, what should I do? Thanks for reading this!!