I can't breathe

Since I was maybe 14 I had fear of germs and OCD. Today I was outside on a walk with my mother and my dogs. Dogs being dogs, one found something nasty to roll around in and when I got to where she was there was a god awful smell, I looked in the ditch and there was a dead animal. I panicked, ok, that's normal. Dead things are really disgusting. But later on I came home and I had a panic attack. I couldn't stop crying and I couldn't feel my legs. I couldn't stop washing my hands, I scrubbed my hands with different kinds of soap for maybe 10 minutes and I still felt gross. I threw away my clothes, I washed all my dogs, cleaned the bathroom, brushed my teeth twice, took two showers, brushed my teeth three more times, washed my hair again, cleaned my room, cleaned my bed and put on clean clothes directly from the dryer. But I still feel disgusting and I can't breathe. Even though I did all these things repeatedly I still feel so utterly disgusting and like I can't get clean. I wash my hands so many times and I can't get myself to stop, and I feel that if I wash them until the point where they start bleeding, there will be more germs and I can't make myself stop. Does anybody react like this and can you tell me what to do? Please?