How do you know when it's time to end a relationship?

My husband and I have been together 7yrs and married 5yrs. Not even a yr after we got together, his mom moved in because she got sick. Which I was fine with at first! Over the years, it has gotten worse. She tries to run my house, and when I don’t do dishes or sweep the floor or jump up and switch the laundry in 30mins and she does it. She makes sure when my husband (her son) gets home, she will tell him everything she did, and then I get called lazy and worthless. I have now recently taken in his niece and nephew. Mind you; I already have three kids. I am not allowed to say the boy does anything wrong because if I do, then I have both his mom and him making excuses for him. I don’t hang out with my friends anymore, I only see my family when they come to me, or he is with me to go see them. I recently downloaded Snapchat. Not for meeting people but for the filters. I’m not getting any younger, and with all these kids and stress, it’s not helping. I took a really cute picture the other day (of course with the filter) and sent it to him before he got off work. Don’t say I look beautiful or anything! This morning he finds out I have Snapchat and bitches at me. Let me say, though; I wasn’t hiding it from him that I had Snapchat. He found out because he went through my phone. Back to the picture. I never posted it to Snapchat; I only saved it and sent it to him. That was it. Apparently, now I’m cheating. This isn’t the first time I got accused of cheating. He accuses me all the time with the neighbors and everything. Sorry, this was so long. I don’t have people to talk to, so it felt good just writing it all out. My question is, when is it time to finally give up and be done. I don’t want my daughter to not have her father because my other 2 have a different dad. But I also can’t deal with it anymore. I take care of everyone else but never myself, but that’s never good enough. Thanks