Dylan-
I agree with Dee 100% that you have to want to get sober first for yourself or it will never work. With me for years I always said I'd get sober for this person or that person and I would relapse because I was worried what other people thought. Finally I said I don't care what other people think and it made things a lot easier.
I also see a therapist and it offered a great deal of support for me. With a therapist all you're going to be doing is talking about your life, I think you would find it very helpful along with this website.
As far as getting back to playing guitar. When I first started playing guitar (I play bass) I was sober. Then I got involved in the whole drinking drug scene and eventually I stopped playing for a long time. I got sober about 15 months ago. I ahve not touched a drop of alcohol. All of a sudden one day, about 6 months into sobriety I picked up my guitar again and started playing and the first thing I thought about was having a beer. Once I got passed the craving though and started playing more I realized I play better sober and music sounds better when I'm sober.
Work on yourself day to day, talk to someone about your problem and you can do it. Don't kid yourself though, it will not be easy but I guarantee you it will be worth it if you work at it.