Why do I feel disgusted with myself?

Honestly you feel like that because you are human, everybody goes through that. If you want to feel better pray about it, talk to some friends, write about it... get your feelings out in a good way. Don't cuddle up with bad feelings, it will only make it worse. Put your head in a positive place, do something that makes you happy even if it's something small everytime you feel bad...it sounds tough but it gets easier as time moves on. That is how you get through tough times- from heart break, grief, loss... small steps along the way and just keep going.