OCD thoughts effects my daily life. Lol?

I have OCD since five months. Like i wash hands with soap when i touch something even in my own house & i tend to wash hands 3-4 times as once is not enough. I am afraid to say or even write the names of diseases like aids, rabies, cancer, asthma, jaundice, or other diseases because i think that they might happen to me if i speak or write them (i really pushed myself to write these diseases even here as i am afraid). One more thing, yesterday a dog barked at me & i just stood there as he came towards me, he sniffed me & went away. But my OCD makes me worry about infections like rabies, tetanus & i am frustrated as the dog didn't even bite me so how is it possible. Even i know that there is no logic in it but still the thoughts haunt me. 8yrs ago a dog bite me & i didnt even tell my parents as i thought it's just a small bite, no vaccine, nothing. So why am i afraid now? Whenever i think of something that fears me i have to go to wash my hands with soap. Like WTF? What will soap do lol?