What I am hearing is that you want others to understand the magnitude of your situation. So, I hear you completely. Drinking is doing nothing good for you at all. You have so much more to live for than a bottle, and a chronic hangover.
These friends of yours may have their own alcohol problem. The only person that needs any explanation is.....No one. Keep doing your thing. When the subject comes up just say " NO, I am not drinking tonight!