wow, it sounds like negativaty and anxiety are really giving you a hard time at the moment. Want me to slap them up the side of the head for you?! No seriously, my heart goes out to you, it's so incredibly tough when you head and your body gang up on you. I agree with twiggy, make a small list, go with baby steps.
If you have any positive memories of times spent with your family try and think of them, and imagine how good it wil be once you have made the effort to get there. Curling up in a ball is very tempting. Don't beat yourself up!