Alcohol just does anexiety and depression even worse, same with extented use of diazepam.
It’s very easy to be addicted to both alchol and diazepam, so I would be very careful with that.
My advice is to stop with alcohol and use as little as diazepam as possible, if I was you I would try antidepressant instead.
You should call your doctor as soon as possible and get a appointment and talk about your conditions and ask about antidepressants.
Mental problems is very common and it’s nothing to be ashamed for, just saying.
Making bad decisions and mess up is a natural human thing, I’m pretty sure everyone have done something they regret (I know I have, several times , I can laugh about it now, but not back then.), it’s a part of being a human I think, so if I was in your situation I would try to but it behind me and say to myself “done is done” and If you have learned from the mistakes or bad decisions I would try to find comfort in that (I know I do.), instead of thinking about stuff you can’t go back and change.