I'm glad you got out of bed yesterday. You can get in to kind of rut. Forcing yourself to do other things does help clear that fog and gives you a little peace of mind, which is helpful when you are sad. It helps to take a break from your thoughts when you can.
Yes, there is no more you could have done. I'm sure you had conversations about rehab and getting help, or even AA. People who don't want to quit are not interested in these things.
You might find these articles interesting to get a more in depth look at what addiction is:
Addiction, Lies and Relationships
Are you actually back working now or still have some time off?