Getting out of marriage due to abusr with two children. My rights.

Im at a loose end and need some advise. My husband and I have been together for 17 years we have s three yo and a four week old. Our relationship has always been rocky from day one and emotionally abusive. I've suffered depression due to the treatment and emotional abuse, the way my husband was brought up he thinks it's ok to treat people badly. I've put up with it because I love him but I'm at my wits end now. We tried to conceive for many years and failed with a few miscarriages I was always under the impression my husband wanted children and a family. We went through Ivf with my son, he was very supportive and acted like he loves him a lot until recently. My husband has been flying off the handle at everything yelling at both me and my son and using threatening behaviour like him going to smack you, I'll knock his head off his shoulders! Yesterday I had to take my daughter to the hospital whilst my husband was putting my daughter in her capsule my son Was behind watching, my husband stepped back on him yelled at him then face palmed him and he threw across the room. I've had enough I've tried talking but he feels he dosnt have a problem and each time we talk he either ignores me or yells at me saying I'm just eating his head with crap. He hasnt acknowledged the existence of his daughter since she was born. He says he doesn't know what to do and she's to small to pick up. I've just been made redundant in my job and will recieve a considerable amount of money to get out. I want to know can I just pack up and leave legally. I have nothing tying me down here, I've tried and he does not deserve his family if he treats us this way he will not change or accept his behaviour. My son is at such a vulunable age where he needs good role models it's hard in this environment. Please help I want out. Legally can I just pack my kids up and leave??