Now that I'm at my computer, I can tell you my own story.
Last year around May, I had been going through a lot of stress as I was about to graduate with my associate's degree after being at a community college for three years due to struggling with depression. I had finally graduated, and it felt like a weight was lifted off of my shoulders, but I was being very heavily pressured to get into the next college at that moment. I began to become extremely anxious and, like you, developed some major panic attacks. These attacks were so bad that I was fearful for my life and went to the emergency room atleast three to four times in just one week due to scary symptoms; at one point, I was actually being demanded to go to a bigger hospital far away from me via ambulance. I actually had such severe panic attacks that I needed a heart echo and a head CT scan to look for stroke. The CT scan was clean, but they found that my anxiety had been making my undiscovered mitral valve prolapse worse. In the hospital, I tested positive for strep despite having no symptoms and ran a course of antibiotics that didn't help how I felt. For about a month, I went through a lot of scary things and had many different tests. I got a lot of false-positive tests; the strep being one, and another being lyme disease. There are other lesser tests I had done, but it's been so long.
I pursued a brain MRI, but my doctor misheard me and ran a neck MRI instead. Regardless, they found arthritis in my neck that was causing a narrowing on the nerves, which led me to finally learn why my neck was always hurting and giving me so much trouble by causing migraines left and right. I got a new mattress and new pillows, which have essentially taken care of the pain, but it does come back at times. I was sent to a neurologist for further testing as the symptoms began to appear neurologically related. Right off the bat my neurologist demanded a brain MRI out of fear of a brain tumor because of the symptoms I was presenting. It was a very fearful week of waiting until the brain MRI was run and we learned that I do not have a brain tumor. He chalked my symptoms down to brainstem migraines, which of course makes sense in alignment with my neck issues. I was put on Amitriptyline 5mg, which didn't help my migraines whatsoever but made me sleep very well and basically shredded my anxiety into nothing.
However, over time, other symptoms lingered, which led me to pursue those. At a normal hearing test (I was born half deaf) to get a check-up on my hearing, I informed the man doing my testing about them. I got referred to an ENT who referred me to a different ENT that ended up referring me, urgently, to an ENT at a major hospital four hours away. I was able to meet my ENT's demands that I urgently go there, going the very next Monday, and came out with a diagnosis for Meniere's Disease.
After almost a year of treatment, I can definitely agree that it must have been my Meniere's Disease and that I have migraines. I've been on Botox treatment about twice, and don't really like it, so I'm switching to AIMOVIG and hoping that it helps. I am, however, now a hypochondriac after having atleast ~20 different tests for conditions. I'm going to head into therapy to try to calm my nerves about medical issues, but it's very obvious that after the rough year I've been through, I became a hypochondriac because of it.
I'm by no means a doctor and I'm not telling you that you might have the same things I do, but I thought that my story might give you insight as our stories are pretty similar for the time being. It could be your neck, it could be migraines, it could be a lot of things; the only way to really know is to be persistent with your doctors and make sure they run every test in the book until you get a proper diagnosis. If you have bad posture (which I also have), stand up once an hour and walk around and look around for five minutes before returning to your seat. Change out your mattress and pillows so your neck is actually supported. After all of that, do yourself a big favor and find a chair that will help you sit correctly before you do damage that's irreparable.