Why do I feel bad?

Why do I feel bad after I have an orgasm, everytime I have one, wether is masturbating or when I’m having sex with my boyfriend, I feel bad immediately like I was doing something wrong or something , ashamed, like I’m dirty I don’t know and iit’s weird cause I know there is nothing wrong with having an orgasm or having sex it’s just that I can’t help it, maybe is something chemical?