Struggling with a Possible Misdiagnosis

I’m incredibly upset. I went to the rheumatologist a couple weeks ago and I was just told my labs were “fairly normal” but they’re assuming it’s ankylosing spondylitis based off of a positive for HLA-B27. Since my labs are “fairly normal” this just means they won’t listen to me any further, but this really doesn’t match up with my experience. Physical activity is supposed to relieve or reduce pain for this condition but it only makes mine a thousand times worse. What am I supposed to do? It feels like I’ve tried so hard and gone through the worst for nothing. I feel defeated.