Alcoholic boyfriend

So I've been in a relationship with my boyfriend for about 2 years. It's never been a good relationship, but I still love him. When we first got together he was seeing two strippers and another girl which he left me for later. When he broke up with her, we got back together. He cheated on me again, sexting and seeing three different girls. He's always getting way to drunk to where he can't function at all and constantly peeing on the bed and on the floor, not showering or grooming or cleaning up after himself. We live together with three other roommates and they dont clean anything or take care of their animals and I end up doing everything along with my boyfriend screaming at me. I've never been more depressed in my life and I feel like if I left him he would hurt himself and I love him and don't want anything to happen to him and I dont want to hurt him. Also, I don't know where I would go if i left. He promises he's going to change and hasn't been cheated on me, but he never means his promises. He lost his job from drinking too much so I have to work my ass off and pay for everything. He cries all the time asking me not to leave him and it breaks my heart. I'm so miserable and I just had two family members pass away. I want to leave but I feel like I can't and I'm stuck. He's very emotionally abusive and has destroyed things around him but has never hit me. But I'm scared he's going to hurt me or my cat, hes so mean to my cat and I would die if anything happened to him. I dont know what to do.