Debra,
I've had osteoarthritis since I was 6 in my hips and knees. I rarely get pain in those joints, so I can attest that indeed OA doesn't necessarily mean pain. In other areas of my body where I have bone spurs, nothing.
And yet I've had chronic upper and lower back pain and SI joint pain, TMJ, foot pain,etc., over the years (those are TMS related). I've come to understand a lot about all of this, after a long journey of frustration and dealing with doctors who were stymied by my pain (NOTHING worked).
All I can say is, don't panic. Step back, and see the words you've used in this thread. Setback, obstacles, pain, devastated. Journal about your feelings. You've mentioned about being scared. That fear alone can thwart your progress. The biggest change I've had to work on is getting more mindful of my words. It may sound strange to really be mindful, but changing your words changes your thoughts, and changing your thoughts will change the physical.
So you have OA. Almost everyone starts to develop some form of it by their mid 30's. TMS doesn't cause OA - TMS causes pain. Two very different concepts, right?
Keep plugging on, and notice when you focus on the "what ifs." Tune them out, because they'll only drive you crazy and keep you focused on the physical, diverting your attention from the underlying issues.
Keep going and focus on the moment only. hope and a positive attitude certainly help. I'm only 10 days in and still have pain, but I am hopeful. Sending you some hope your way.