Should I leave? Don't know what to do?

Me and my peice of a husband have been together for almost 7 years. Our relation hasn't been the best. He's not perfect and neither am I. But he does things that pisses me off so bad that I actually want to hurt him!!! He won't go out and find a real job, although he does this banquet serving thing where they call him if needed. I work all the time, pay all the bills. I have 3 children from a previous relationship and all are by the same man. My kids used to like him but now they see me stressed out and upset all the time. He asks me for money knowing I need to pay bills and buy things for my kids but it seems he doesn't care. He also gets upset at the fact that I haven't had a baby by him, although I did conceive but it was an ectopic and I lost the baby and a tube. That was almost 3 years ago. I don't want to have a child buy him knowing that he will do absolutely nothing but sit on his *** while I take care of him or her!! He also has a dog that he keeps in the house, she pooped in her cage the other night , I had worked almost 9 hours and wasn't about to clean it up!! Do you know because I asked him to clean it up he didn't?!! I had to get up and clean it up myself!! OMG!! I was so pissed I could have hurt him something serious but I held my peice! Sometimes I just want to pack up me and the kids and just frickin leave his a$$ ! I think I would be less stressed and have at least a peace of mind! I don't understand him. I go to work and he sits here all day doing NOTHING! I mean not even a washed dish, clothes nothing!! I be so tired when I come in and I don't want to have to do more work when I get home. Who does after a hard days work? What can i do to let his lazy, selfish prick that I am tired and fed up? Has anyone been through this? If so did you leave? What drastic measure did you have to take? Because I am sick of it!