I said "NO".. is it really OK?

I should learn to say "NO" without feeling bad.

I should not feel remorse after declining a request for favour or invitation or any of the sorts. Of course, there is valid reason as to why I declined. However, this sickening feeling of remorse is haunting me nevertheless.

By right, I should just ignore it as the person has already affirm that it was ok. But i keep on asking, was it ok? really ok? really really ok? ... Oh my chest hurts......

Whatever! I should just take it as it is... if he says it is ok then it is really ok, right?