Stay or leave husband?

my husband and i are not to getter right now i filed for divorce. but we splite up for 2 months and then he found a girlfriend and so we didnt talk for about 6 months and now she left him to go back to her husband. he told me that he would like to get back with me but i said let me think about it. but the next day i found out that he started drinkin and doing drugs. he tells me he wants to be with me then the next day he dont then he tells me he wants to make it work then he dont. I tell him we need to talk and he tells me tomorrow but tomorrow never comes. he tells me he loves me and but dont want to be back with my baby and i. he told his cousin that he wants to finesh his partying first.
I dont know what to do. should i stay or leave him.