peridontitis at 19... any advice?

hi everyone. this is my first post in this discussion and i’m looking for advice. some back ground, i’m 19, female, 119 pounds and suffer from chronic EBV (mono virus) and hypothyroidism. I got sick with mono in october of 2017 and never bounced back. my gums began bleeding everyday when i brushed back in jan 2018 and never stopped. i foolishly didn’t go to the dentist, never floss, and only brush once a day. i recently have gone through severe emotional trauma and my gums got sooo bad. i went to the dentist and he said i have bone loss, painful pockets, and lots of bleeding. i have been brushing after every meal, flossing, and using mouth wash. anyone deal with Peridontitis? and have any tips for me? will brushing help stop the disease? i’m a hypochondriac so i’m scared this means i have an underlying disease. thank you!