Family issue. Situation. please help.

My husband is an alcahol dependant who is scheduled to start an anti addiction therapy from next week. I have been trying hard to keep him away from drinks for the last few days with little success. He has a group of friends outside work who he parties with all the time. Now he says he wants to meet them one last time before he goes into therapy so that he can personally say goodbye. He is leaving town with them for ,2 days leaving me alone at home. I am 25 weeks pregnant and have a 7 year old daughter to take care of without any help. I feel this is unfair on his part. I tried my best to convince him not to go but he is very stubborn and disappointed that i am not giving permission. He has agreed to terminate all contacts with them once the therapy starts. But they are bad influence and he gets completely out of control with them.I am unsure of how to deal with this situation. Please help.