Please don’t be scared. I had to think that I was living with it long before I knew I had it. I’m surprised nobody did x-rays all those years that you were getting treatment at pain management, so they knew what they were treating.
Anyway, the rheumatologist will certainly know something about the disease. It’s just the medication’s that he has in his toolbox, will not help with this disease unless you have other inflammatory conditions. In the meantime, try to relax. As we all know getting upset, does nothing to help. In fact, the tension can make things worse. There are several people on this site that have this condition. Although so far, I think you seem to be the youngest diagnosed that I am aware of on the site. I wish you the best of luck at your visit with the rheumatologist and that he gives you all the knowledge that he has and point you down the right path. Come back and let us know how your visit went. 🙏