Drinking and doing drugs was like an automatic maintenance system for me. I didn't have to deal with stress because I could just go home and get high or drunk at the end of the day. When that automated system is gone, manual maintenance is required or the machine will rust over and fail.
Simply put there are things that I must do now in order to feel my best, I can no longer let life happen, I have to engage it and sometimes push back when it chooses to throw difficult things at me. Exercise, every single day in the form of calisthenics or walking along with diet have gone a very long ways for me.
Good luck and keep up the good work.