T.F.
First of all...........YOU are not a bad tooth mom. It happens. I was in the same boat as you at one time!
I was motified when my daughter had a cavity at 3. We fixed it and went on.
She is now pushing 13 (12/27) and since the cavity at 3 on a baby molar, she has had NO cavities. We did get the sealants on her teeth as recommended by her pediatric dentist, Dr. Tipton Asher, and we have had NO issues since.
Believe me, I have cringed when I took her to Dr. Asher because you know how kids can be with brushing and flossing. I have been amazed at how he and his team keep her on track for dental care.
It will be ok.
Susan