Then leave him. Women's aid now. If you love your children, then you need to get back in contact with women's aid. Sod what your parents or anyone else thinks. your biggest job right now is to get safe and away from this man. Make the call and get the hell out of there. This is no life for you or your kids, or your parents (but most importantly you and your kids). Women's aid will protect you from him and will get you on your feet in terms of sorting out benefits etc.
Right now, this is your most important and only job: use women's aid, get safe, then get your kids. Call WA again, please, as soon as you can.
And I speak as a major pet lover who has horses, dogs and cats - your pet is not more important than your kids. Re home, put him down, take him to a rescue or foster. Or just leave regardless and report him to the rscpca. Do you want to get 10 years down the line and have to be the one who tells your children "sorry I didn't leave your abusive father and look after you myself, but the dog's safety and happiness was more important"? This is a bit of tough love from me, and I'm sorry to sound so harsh, but just imagine saying that to your gorgeous little kids when they are teenagers and you've missed out on all their triumphs and achievements, all their firsts (first sleepover, first lost tooth, first prize at sports day, first date), and missed out on comforting them as they make mistakes and feel ill and ask for their mum.
Call WA now!