I'm So Lost. Could You Help Me, Please? :(

Hello everyone,

I'm writing here kind of as a last resort because I really don't know where else to turn to. I've been reading a a bit around the forum and the community seems SO welcoming and kind I thought I might find some help/suggestions here, please.

My last few months have been a completely draining vicious circle between doctors, tests, hospital visits, anxiety and co-pays.
I'm a 30 year old woman and, until July 2021, I was physically perfectly healthy. The pandemic took a toll on me (as I guess for a lot if not everyone of us!!) but up until then I've been practicing sports and going to the gym very regularly. I love(d) to run, doing strength and cardio classes and swimming. During the pandemic, I did my best to exercise at home following strength conditioning & nutrition plans. I'm very petite (5.2) and relatively light (110-112lbs).
In June 2021 as the restriction eased a bit where I live, I picked up kickboxing and was SO excited about it. I was enjoying every single class and giving all my best...until that terrible pain started.
On the night of July 14th I woke up in the middle of the night because of a back pain I never felt before. I thought it was my kidneys at first but I didn't have to go to the bathroom and was fine when I did the following morning. I felt as if my mid-low back was tired, sore and I thought I just slept in a funny position.
Ever since that night it was a nightmare. The pain lasted for weeks, then went away, then came back. It was ONLY at night. I saw my GP who prescribed some stretching. Did that for a couple of weeks to try. It didn't help. Went back to the GP. Was referred to a back specialist.
He told me "sitting is the new smoking" (to which I agree!) and told me I'm ok, just watch your step count and try to move more. I thought it was weird because I've started kickboxing for this very reason?!?
I added walks to my routine, watched my sleep positions, bought lumbar pillows, tried with heated patches. The pain was there and it didn't seem to respond to anything I tried.
The weeks became months and the doctors started ordering tests on tests: MRIs of my back, tons of bloodwork, even a CT scan of my abdomen/pelvis that showed a gallbladder stone and a pancreas cyst that got looked at by a GI. Everything turned out to be ok/clear.
Still, the pain persisted and "just like that" (or not really because I struggled SO much during those months) it was November and time for a holiday.
While there, I was enjoying a back pain break but instead developed tingles and burning in my thighs. The doctors did more tests, even got looked at by a neurologist. Nothing wrong, apparently. We decided it probably was the hot baths I was taking so I stopped those. And, indeed, the tingling subsided, thankfully.
But the back pain gradually came back. And with it came some 4-6 pounds sheds, a lot of worry and disruption of my sleep. This weird pain that only comes at night and leaves me a bit stiff in the morning for a while...Which brings me here today, I guess.
I've been told by the 7-8 doctors I saw that I'm ok, healthy, and that I'm just very anxious. Slowly, the stretching and postural advice was replaced by "take these antidepressants".
A few days ago I crossed the mark of my 8th month of dealing with this. And it's honestly SO frustrating. I just wish I could get an answer.
I wish the doctors wouldn't think I get the back pain because I am desperately anxious but, on the contrary, it's this weird back pain that causes me to be so worried because it is like nothing I've ever felt before, I swear.

I know it's a stupid thing to do, but in lack of a diagnosis, I went on the web and searched about this weird symptom. Besides the most terrible metastatic/cancerous outcomes (which my doctors say it's not likely but who knows at this point... 🙁. I repeatedly saw the AS profile and could honestly see myself in a variety of those symptoms.

My spine MRIs and X-Rays all reported degenerative changes in my spine and some disc bulges and protrusions, along with some bone spurs. All these were labelled "minor findings" that couldn't justify my pain. Some doctors used the term "arthritis/osteoarthritis", others said "you're ok". I even went to Physical Therapy and was only told I have an impaired development of core muscles but otherwise I was good to go and the therapist discharged me.

One night when my pain woke me up, I tried my best to stop the scary thoughts running in my head and tried my best to tune in to my body and ask "what's this that I'm feeling?" and all I could think of was "my back feels "inflamed"...

I also saw a (very good!) chiropractor multiple times to no avail, unfortunately. Just today, he told me "I'm way too young for all this" and did say that my night-only pain "is strange". He thinks I might have torn a ligament or a tendon. We did a lot of work on my psoas muscle. Than I thought ok maybe my psoas ligaments are inflamed? The chiropractor (bless his soul, the only one who asked me) asked me to describe the pain in detail. All I could say is "it doesn't seem to follow any specific pattern besides I have it at night only and sometimes I do feel as if it gradually progresses (sometimes it starts slow then intensifies; other times it starts intense to then subside in a few days). To this the chiropractor said that it feels as if my ligaments are trying to heal themselves. I like that but I am not sure...

I also remember last week I did a massage with a very good therapist but went home with a really painful spot around my sacrum after that lasted for a couple days. Reading that AS patient often exhibit sacroiliac tenderness that left me wondering.

I know I've just poured a lot on whoever is reading this but I'm just SO lost right now. I just wanted to be super detailed in case anyone could please, please, please help.

Has anyone with AS ever been through something similar? Is the inflammatory back pain route the way to go to approach this pain (I did some bloodwork C-reactive protein, ESR and others and they all came back neg or at least not high levels).

Please, I'd appreciate some guidance as I am fighting SO SO hard but it seems like all my doctors can see is that I'm just a very crazy and overly anxious person. I respect them a lot and I am also ready to accept the anxiety thing but something inside me tells me that's not the only thing at play. I also worry that my inability to better explain my pain or "produce" it when I'm at the visit is leading them away from the right diagnosis. 🙁

I'd really appreciate your input in this. Thank You SO much for your kind attention.