If we know how old you are and if this could be arthritis, etc. We could help.
1. See a doctor
2. Most likely see a physiotherapist with experience with knees. Your doc will advise what to do.
3. NSAIDS can help but I find they do next to nothing as mine isn’t arthritis. I like Advil but there are NSAID’s that you apply directly to the knee. My father has success with the latter but he has arthritis.
4. Glucosamine, MSM, Chon, etc.
5. There are peptides that are supposed to help heal but I would always go 1-4 before considering number 5.
Good luck