You are not disgusting. You musn't think things like that because it's not true. I've thought about things along those same lines. The other night I impulsively though about falling down the stairs and getting really hurt... horrible thought and I would never follow through but I just think about it sometimes. I would definitely talk to your therapist about it and try to work through it (although I can't say that I will...). The human mind and why we think what we think is so complex...