can I open up a bank without my bf knowing...

We have a joint account but I also want to get a separate account. I'm going to start working and using our joint account to have the money deposit there when I get paid but I'm planning to take out some and keeping it in my serpate account.. I'm doing this because I don't have anything on me right now. he is constantly kicking me out/breaking up with me calling me a bitch. this morning he got mad when I asked him if he can help me with the babies and told him not to smoke. he called me a bitch n said I don't do anything, said the place is always a mess and I don't cook everyday. I take care and do majority of the work with the kids. I'm always the one to feed them, bathe them, wash bottles, put them to sleep. he only does things if I ask but nothing else. he doesn't work either only about 6 times a MONTH when he feels like it. I feel worthless I feel sad. anything I do is never good enough for him he says I make him miserable he said the only reason he was with me was because of the kids but quickly apologized one time. I'm not perfect but I grew out of bad habits and changed and he laughs when I explain in what ways I changed and says I'm full of shit. iam tired iam exhausted mentally n physically I'm not allowed to feel anything or he threatens to leaves. I don't have any money or a car I have 2 under 2 and scared where I would be. I always feel like I have to prove him wrong which is really stupid I know. I was promised a min wage job and I want to leave so bad. 3 years of me trying and nothing is ever good for him. I don't know where to start or what to do. I can possibly save up without him knowing for a few.months for. car I just don't know I'm scared.