I went through this pretty hard in the beginning. I remember when I posted sort of the same question someone asked me, "what do you like to do". At that time, my only answer was "I like to drink". After a few more days I realized what my new hobby was, it was exploring new things to do!
I spend my evenings when not exercising or reading, researching whatever pops into my mind that I want to try or learn. There are no boundaries now and this was the greatest realization I have ever had. I can do ANYTHING, where as for years I couldn't.
Can't say I have found any one thing that really gets me excited, but just having the opportunity to is what I hold on to and that is what I do with my evenings.
I can't wait until spring comes and I have daylight again after work, then I am out of the house! I hate cold, I hate darkness so I really picked the wrong time of year I guess, but I am making it with books and exercise.
We will find our way kitfreed, this I believe.