Hi OP. I’m really sorry you are going through this, it’s really tough. First off, yes, I would stop drinking around him. For one thing, he can see it as an excuse to carry on, and for the other, it may lead to feelings of guilt for you down the line. You have enough on your plate.
How can you help him? You can’t. He may have started drinking because of his depression, but he is now (more than likely) in full addiction territory and the drinking is its own monster, regardless of the depression. Worse, the drinking may very well be negating the effects of the anti-depressants and the drinking itself causes additional depression. He is in a horrible spot.
You are completely powerless here, I’m afraid, and I know it won’t be what you want to hear. This must be horrible for you (I’ve been there too) and your best focus would be on yourself. I recommend getting in touch with Alanon and maybe some counselling for yourself. It’s an excellent way to vent, as well as learn more about enabling and codependency.
Your DH will only stop drinking if he’s ready and many alcoholics never reach that point, I’m afraid. You could phone his GP. They won’t be able to talk about him to you, but they will listen and make a note on his file to raise at his next appointment.
You could phone a rehab clinic or make an appointment with an addiction counsellor. None of it will do any good unless he wants the help.
How are you feeling about the marriage? I stayed in mine far too long before I eventually called time. It was a very good decision and I have no regrets about making it. I do wish I’d done it sooner, though. Be very careful how much of yourself you are willing to give to the slim chance he might get back on track. Some people do it and I have massive respect for that, but you should be really clear that they are very heavily in the minority, sadly.
Lots of luck to you.