It seems like you've simply lost your zest for life.
I hate to recommend drugs or alcohol but they've always worked for me. It's amazing what a low dose of a stimulant can do for a person's cognition, confidence, and ability to socialize.
If you truly feel all is lost, maybe you just need something like that to 'wake you up inside's I'm the same way as you, missed opportunities for days, but on stims I just feel so Alive. I feel like a bad friend for recommending drugs but some of us just need a little tweak in our brain chemistry and that instant dopamine/serotonin really hits the spot