Things I did to fix my life:

Quit smoking: read Allen Carr's Easy Way to Stop Smoking; 20+ years smoke-free.
Quit alcohol: read Allen Carr's Easy Way to Control Alcohol; alcohol-free since august 2016.
Improved posture: Alexander technique classes – expensive, but more than worth it. Don't get tendinitis in my shoulders anymore either.
Lost weight: calculated my TDEE (total daily energy expenditure), ate less calories than that, logging everything I ate as accurately as possible. A food scale is indispensable. For health, I also eat lots of fruit and veggies and make sure to get enough protein; these also help you not get as hungry. /r/loseit/ is a great resource. Here's a before & after pic.
Got fitter: joined a fitness bootcamp 2x/week. Started running 1-2x/week, too.