Hello and welcome to the forum, Aper.
You ask what to do to support your partner, your gut instinct is telling you to give him space, that is fine.
I encourage you to look after yourself especially as you are pregnant. Please have very low expectations of him quitting. From all you have shared, he does not sound like a person ready and willing to do the very hard work of quitting and then working a strong recovery program to support him in staying quit.
Is the doctor offering any support for him? He needs professional support and the support of fellow quitters in this very difficult journey.
My late alcoholic husband was on anti-craving meds for a few weeks while he was in hospital. He was brought home by ambulance transport and was pouring himself a whisky as the ambulance was starting its engine to drive away.
The real problem had not been addressed which is the thinking process that a person who uses alcohol has.
I hear what you say about how good he has been to you but please do look after yourself and your developing baby. A resource that a lot of us here have found very helpful is the Al-anon program and also the book "Codependent No More" by Melody Beattie.
Wishing you all the best.