Diagnosed with lumbar spondylosis but all signs point to AS

Has anyone else had this trajectory? I have low back pain and inflammation that is SO much worse overnight and in the morning and gets better with movement, but too much can put me into a flare that takes weeks to go down. I also have pain and inflammation in my knees which I am only now starting to look into (because all the appointments for my back have taken precedent).

X-rays showed unremarkable SI joints however that’s where all my pain is, not around my spine, although it is a little hard to tell cus all my muscles around my back are also tender and locked up (guarding?)

I’m really new to this whole world so hearing others personal experiences would be appreciated! Thank you!