I think vaccines were responsible for my PMR also. I had 3 vaccines in 4 1/2 weeks in the fall of 2020- a flu, a pneumonia, and a tetanus. The flu and pneumonia were my first ones. Then, a few weeks later I started having pain. For a while I thought it was caused by repetitive motion (I'm a cellist) but eventually it became much worse every time I exercised..even yoga. I knew there was a big problem then. Eventually, I put 2 and 2 together about the vaccines as a possible cause. I understand how you feel. It's hard to know whether to get vaccines or not now. I went ahead with the COVID vaccines and boosters but didn't get a flu or the second pneumonia this fall. It sounds like you've been through a lot.