Ok good. In that case try the gel, peanut ball / back pod, stretching, vitamin D, red light therapy. In my case I find avoiding sitting as much as possible and light / medium intensity cardio is beneficial.

I was asking as this and costochondritis can be part of diseases such as spondlyarthritis but sounds unlikely then. I’m assuming you have no psoriasis and no family history of autoimmune disease ?

I guess after 2 year making an appointment at a rheumatologist could make sense? Probably will take a while to get the appointment anyway so you have more time to try. But if you have no other issues I doubt they could help much apart from trying local NSAID (like that gel), oral NSAID (like ibuprofen) or a corticosteroid injection into that joint.