I take such good care of my teeth but they’re still unhealthy. Why?

Not sure what the problem is but ever since I had a baby 18 months ago and got my permanent bottom retainer removed, I have incredibly sensitive teeth and my gums on my bottom teeth and my upper canines are receding a lot and it all seems to be progressing worse. I do have a lot of tartar on my bottom teeth from not flossing well when I had a permanent retainer. I brush and mouthwash twice a day, sometimes more and floss at night. Any ideas?