Hi Spirit. When my S started I joined a few volunteer groups and started making a concious effort to not sit at home all alone. Especially when I was feeling down and not like going out. Even if it was just to the beach, I made sure I got out of the house for something that didnt just have to do with work or school.
Yes, you just go dark and wait... while thats going on, you have a great opportunity (It may not seem like it right now, just beleive me) to do some really great things for yourself. Hit the gym, start tanning, buy new clothes, get your hair cut, start hiking, volunteer with the fire dept, you get the idea. Start doing things that make you feel good, and let her worry about whats going on with her.
Im sorry that you find yourself here, good luck!
I guess I gave the wrong finger to the wrong man...