Welcome! I'm sorry for your situation.
Does your husband want to stop drinking? If he is not motivated to stop drinking, there is not a lot you can do. The therapist who told you it's not good being the Booze Police is absolutely right. It may seem satisfying to you in the moment to see him caught, but it doesn't really help him or you. In the same vein, it's not up to liquor store clerks or owners to not sell alcohol to him. He may look like he drinks heavily, but alcohol is legal, and it's up to your husband to decide to not buy it.
My suggestion is to create boundaries for yourself and your teenage children, keeping in mind that boundaries are not rules for your husband. Also, AlAnon in your town or city would be a good support for you and there is lots of support for you in this forum. I hope that you can find some peace.