Scared to stop gaming because it's all I've ever known.

My whole life I've suffered from anxiety, shyness, and recently bipolar type 1. I always hide from my problems via games. I'm 23 and I live at home with almost no ambition to be "successful". I'm in treatment for my problems and on meds but I'm honestly content with being a loser. It's easy. So I have 2 questions.

1. As an atheist, I feel as though there is no reason to be successful because I will die anyway, how do I break that thought process?

2. I'd like to replace gaming with something productive. I've drawn in the past but i do it for extrinsic reasons. I'd like to find a hobby that is both productive and relaxing. Something i can get lost in. Any ideas?