Failing at parenting

I don't know what I am doing wrong or what I should be doing differently and I am looking for advice.For some background: I have two boys ages 3 and the other turns 2 next month. I am currently living in a women's shelter with them because we had to leave the house after I called the police and dcs on my husband for child abuse.My kids are out of control when they are with me. When they are not with me I never get any complaints about their behavior and everyone always tells me they are so well behaved. But when they are with me they are horrible.They have no respect for me and they defy everything I say. They tell me no all the time. They fall limp on the ground all the time if they dont get their way. They run away from me. They hit. They haven't been going to sleep until around 11 and we have to get up at 4:30 in the morning. I have no control over them and its driving me insane.They were "spanked" by their dad starting before they were a year old. Often these spankings would leave bruises. This was how my husband disciplined them. I have tried the approach of taking things away like a toy or tv time, but its just not working. I am going through extreme stress myself right now and its so hard to not just give them what they want just because I can't deal with the awfulness of their behavior on top of everything else. I bought some parenting books, but I wasn't able to take them with me when I left the house.I have been doing fun things with them and taking them places to have fun, but I always regret it because they are angry, crying, complaining and whining the whole time.They were not this badly behaved before we left my husband so I know some of it is from the changes that have been happening. I just feel like such a failure because I don't know how to help them and their behavior seems like evidence that I have raised them poorly. Any help would be greatly appreciated. via /r/Parenting http://ift.tt/2BsLAPT