young married 4 kids and scared

i married at the young age of barely 18.I was dating my husband for 3 short months. I got pregnant, I wasnt trying to get pregnant either i was on the depo shot birthcontrol. When I found out everyone in my family was basically forcing me to get married.So I did because i couldnt take it anymore. I never did have the " im so in love" feeling with him. After we married and moved in together, the real him started to show. we now have 4 children. all girls,7,5,1, and 1 on the way. And I feel forced into haveing to have sex. its to the point where i hate to kiss him or even be around him, he tells me things like "all woman are stupid bitches" "your a dumb bitch" he constantly pushes me around. he's a big tall man, and uses that against me. he yells and curses at me and the girls everyday. he gives me horrible panick attacks, me makes me cry day in and day out. he causes scenes out in public by cursing and screaming at me.a few years ago i tryed to move out and get me and my girls out of this situation and the kids were in the car and he choke slammed me and jumped in the car and took our kids to his parents house and left me at the house with no vehicle and no phone, then he went to the cops and told them that i beat his ass, only because he knew that whoever got to them first had the case started then he had the guts to come back to our house and tell me these things then looked me in the eyes and said dont think your getting the kids bitch.i didnt want to lose my kids, afterall i dont have a high school diploma and i have been an at home mother since i was 18, i am now 26. and i was scared to lose my children i am the only one who takes care of them i cook,clean, do homework,get the ready for school, i do it all. and im scared for them i dont know what they would ever do without me.i am at my wits end and dont know what to do anymore. i want out and i feel like he wont let me, physically he wont let me. he will fight with me till the day i die, just to make my life miserable. i dont want to take the kids away from him at all they love their dad. i just havent been happy since i was 18 and i want out i want to be happy and not live like a hermit afraid to say or do something wrong.and im sick of him always screaming at the kids for no reason just because he has a terrible temper and short fuse.i just dont know where to start or what to do. please im in dyer need of some advice from someone whose been there. or at least someone who knew someone in my situation