congrats on 5 months - I was where your are 7 months ago. I had much different circumstances surrounding my life. Before I quit drinking I worked the craziest hours imaginable. I had no outside life from work and then spending off days with people I worked with. Then, no job, work 'friends' avoided me. I spend an awful lot of time on my own. I took the proverbial 'year off' from a lot of things. But I went fishing on my own. It's a secluded kind of thing anyway. I am just now starting to seek out new things. It takes time to find your sober self. I'm much older than you. I understand how drinking is part of the social norm for your age group.
Give yourself time. Try to find new interests if you can. I just got into learning a new instrument. Try to find a hiking club or something in your area - I know they exist.
Take a ride up to Hawk Mountain and get some fresh air. The important thing is to be happy with who you are becoming. It's a journey. The more time you get the more you will begin to branch out into other interests. Don't get too frustrated. You are so young with so much time. Find yourself. Really.