Hey,
Congrats on your for taking this huge step, i had the same issues, pills and booze. Rehab, taught me a lot. It was my birthday yesterday, it wasn't easy, but i managed, went for a nice dinner. one of the perks for me, is i've been saving so much money, im able to treat myself once in a while, kind of like a reward for the hard work. i'm only 3 and half months, it's not an easy process. i was severely depressed for quite a while, but doing much better now. I'd suggest looking in your area for some kind of support system, if AA, or NA isn't for you, there are a lot of other options if you live in or close to a decent sized city. It's nice to be around people who understand, and have been there.
The hardest thing for me, similar to you, is what to do with my time, I'm still struggling with it, with my therapist, we talked about short term goals. You could even do that yourself, and make a list.
I can relate a lot with you, if you ever need to please PM me, we can share ideas, or you can vent if you're having a rough day.
Don't give up on yourself, you can do it
~Hollow