What do i do about my husband? i want to make things work?

This will probably be long. My husband and i have been going through hard times for a while now. I have known him for 7 years and we have been married a little over 1. We have a 6 month old daughter. What i didnt know until after we got married is that he is a drug addict and abusive. Hes not abusive all the time. Just when going through withdrawals or drunk. But it started when i was pregnant and happened about a week ago the last time. He has slapped choked and punched me in the face. One night he also came home drunk with a hickey from a 17 yo girl he buys drugs from. I love him and i know this all stems from his drug problem and he says he will get help. He even started outpatient treatment. But he has lied to me many times about quitting. I am very stressed about this. We fight all the time about it and money because i am the only one working and only pt. And he would take money and spend it on drugs. I want to believe that he can and will get better but i am so afraid of hurting again. What do i do?