S.P.
First, I am so sorry you had such terrible experiences with the dentist when you were a child. No one should have to go through those kinds of experiences. I know you can't change things now but, as you may already know, if you visit your dentist regularly and take care of your teeth as your dentist recommends, your gums will become more healthy and much less
tender and fragile . . . which will make future dental procedures much less uncomfortable. Meanwhile, for your next cleaning, I wonder if you could allow yourself to simply let the dentist give you local anesthesia before the cleaning. The administration of local anesthesia isn't nearly as bad as it once was. They put a topical anesthetic on your gum before injecting the main anesthetic into your gum.
Also, even though you didn't ask about this,
I'd like you to think about how your attitudes about dental health
might affect your children's attitudes as they are growing up.
Hang tough, mom!