Abusive partner

So I’ve just found out my partner has started using heavy drugs... he has become very abusive both mentally and physically. (Mainly verbal) I’m scared & when he goes out I find myself not sleeping or sleeping for maybe 2-3 hours a night until he comes home, sometimes he doesn’t return for up to 4 days.

I’m not strong enough to leave even though everything in me is telling me to walk away, I’m 23 weeks pregnant.

Has anybody else had a similar experience?