First of all who told you have oa ?
I am asking because it is not true
Your xray was taken obliquely hence giving you a false interpretation
I would request you to get clinically examined as you may be having a meniscal injury as per your history
And then can i Or for that matter any proper doctor can suggest you the treatment
Next Steps
If you are affording you can get MRI of your knee done as your xray seems normal
Health Tips
please wear a long knee brace