I feel my husband is mean to my children?

I need some good advice. My husband is a good person in general. He has turned out to not be good father material tho. I have a 4 yr old son from a previous relationship, we have a 7mo old son together and he has a 7 yr old son from his previous marriage. The only child he is nice and loving to is the 7 yr old. He won't do anything with the rest of us unless the 7yr old is here and he wants to do something. My hubby does nothing but talk down to, belittle, and yell at my 4yr old for nothing other than being 4. For example, He is teaching my son to not share by telling him he can only touch his own toys and no one elses and hurts his feelings several times a day. My hubby also has no patience for our baby. Example: he is learning to crawl and sit up. If he falls over and bumps his head my husband will yell at him for crying, call him a "screamin mimi(?)" and put him in his bed, screaming. The 7yr old never gets in trouble for anything. Well he did once and my husband bawled about it. The 7yr old isn't a bad kid but is very disrespectful to me and hateful to the little ones when my husband gets home. My husband also sucks up to his exwife every chance he gets. They are divorced because she cheated on him. I think he still loves her and prefers her to me. There is sooo much that happens on a daily basis that I could never fully address on here. Hopefully I've been able to share enough to prove my point. I want to leave. I want to take my kids far away from him. I can't talk to him about his behavior. When I try he yells at me and tries to make me feel im wrong, or stupid or a sucky mom. At meals (that I was raised to believe was family time) we are expected to remain silent. No talking. My husband says it's disgusting when the 4yr old talks with food in his mouth yet the 7 yr old puts his face on the table and scs food off the side of his plate into his mouth. Every meal. I seem to be the only one that notices. Ugh! I could go on and on. I want to leave so bad. I haven't worked since I had the baby tho because I'd only make about enough to pay daycare. I have no money and no place to go. I don't want my kids around this. I want them to be kids! To be happy and learn good things and not be afraid to ask questions. I don't want them to be like him