After quitting a harmful dependencies it is reasonable to thinking about substituting them with useful habits. Otherwise dependencies would be back even in a more sever form. After all it's interesting to investigate what other good thing you could appropriate in your remaining life time. Here a list of some ideas:
Run
Read
Meditate
Play musical instument
Do art! Paint, Dance, Sing, Advance
Write a diary or blog or whatever you want
Start a business
Join a community with shared interest
Spend time with people who matter for you the most