Years of drinking alcohol damages your brain which may cause depression and all sorts of side effects. If possible I would suggest getting a good physical with labs to see if anything is out of whack. It could be something that you are not aware of that is causing the blues.
For me after 90 days life is getting better by the day. I still have aches and pains from being up in years however mental problems I carried for so long are MUCH better. You may be in a stage of recovery where you're in a fog and nothing excites you. Just hang in there and if you'll be diligent in your sobriety, things are bound to be on the up. Another thing you might want to consider is joining a gym. Exercise has a way of taking the blues down the toilet. Keep fighting for sobriety ! You can do this!!