tooth decay

Ok so I'm 22 years old and I brush my teeth at least twice a day, use the floss picks and use momouthwash, 3x a day on my days off. But yet my teeth are rooting away. I am highly allergic to,novicane And that is half the prolbem. I have all ready lost one tooth to this prolbem and a few more of my teeth have holes in them and are really yellow and black. I don't understand what the prolbem is an. I can't find a dentist anywhere in my area that does not use novacaine. Can any one help tell me what's wrong.