But many people say "be sorry to do" means you are going to disturb someone, so you feel sorry. Instead, you should say "I'm sorry for making you angry"...
Thanks so much for your help!That is not true.
There are two different expressions:
I'm sorry to disturb you means you are going to disturb someone.
I'm sorry for disturbing you means you have already disturbed them.
However, since the fact that you are saying sorry means that you have already disturbed them (in order to apologise) the distinction is rather theoretical.