Time to rediscover who you are again. Minus the fun and excitement of discovering things. It's hard to feel confident when you've been rejected and it's more like you feel worthless. I know exactly how you feel. You want somebody else to take away the hurt but in this current state it's almost impossible because you aren't projecting that confidence and self security. I always thought it was funny that I was so self confident with girls when I had a girlfriend, I'm trained to feel like I need one.
Being on your own right now sucks but it's healthy to break that dependency on another. You are going about things the right way. You shouldn't be giving up on your working out and what you were doing before either. You are doing this for you remember, not for her. No reason to give up just because you've accepted it's over. You have that determination in you. Put yourself in positions to meet new people and even if you don't feel like pursuing somebody else, it's okay. It's really funny how when you aren't looking, things can and usually do just fall in your lap.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.