I don't think you're overthinking this at all. You may be making a few excuses but we've all been there. I was a consistent drinker for 12 years and I could have written your post 3 or 4 years ago. All I'll say is that not getting drunk is a really bad sign and that eventually your body will tell you it's had enough. I don't think there's a way round that. Drinking too much over a decade will do damage. My damage manifested itself both physically and mentally. I had still not acted crazy or effected my social life or work but I still had major problems from my alcohol intake. In a way I quit drinking because I had to, but it has had such a positive impact on my life that I wish I had done it sooner. My mental outlook improved almost immediately and although it has been a struggle at times it has been very rewarding and I have learnt a lot about myself. I am strangely much happier sober. I never imagined that would be the case. I hope you consider quitting, at least for a while to see how you feel. That would clear up the question of whether you can or not anyway. Incidentally anyone can give up drinking with the right support and guidance. No one is doomed to drink forever. Glad you're here x