I Have Two Teeth, Upper Left, That Are Both Extremely

I have two teeth, upper left, that are both extremely loose. I am 52 years old, and I have an appliance that has a fake tooth that rests in between these two teeth (it got pulled and I couldn't afford a bridge). I have had a grinding problem when i sleep for years. i wear a mouth guard to try to protect my teeth. The looseness has happened within the last two to three weeks. Gum is very sore and I cannot eat anything of consistency because it hurts. Do I have peridontis or gingivitis or something? I brush twice a day and floss periodically. Do I need to see dentist right away?