I think I want a divorce

As much as it pains me to even think about it, I feel it's what best for myself and our children. My husband comes home to drink and lay on the couch. I must be the one to take care of the kids sun up to sun down and then take care of him and the household. He doesn't help prepare food, clean up after himself, help with our children. Nothing. He's even gotten to the point he lays his stuff around for me to go around and pick up after him. I suffer severe depression. To the point most days I hate trying to do anything that revolves me moving more than three feet but to make sure my girls aren't living in filth and they have clean clothes I push myself hard, which leads to me laying in bed most nights either praying for God to take me away or thinking thoroughly thought through plans of ending my life. The only thing holding me to this earth are my children and being pregnant. This baby was planned. And now he makes me feel as if we made the biggest mistake of our lives by bringing in another baby. He's not always been like this. He only recently started the drinking everyday. At the moment I can't be intimate but I make sure I show in more ways than sex. I lay with him, I kiss him and hug him. But with the drinking I don't want to be anywhere near his face. It's to the point I want to start indulging in liquor and alcohol to try and cope and stand to be around him. I only refrain because I'm pregnant. I just feel as if a divorce or seperation is in order. I'm sitting in the bath while my children are playing writing this and crying because I have locked myself in the bathroom wanting to self harm as I've done before but I'm trying so hard not to. At some point the depression overcomes how far I try to hold on.