Persistent pain post-anterior cervical fusion C4-C7?

Summer '22 I had C4-C7 fusion due to a variety of pathologies including arthritis, herniated disk, and C6 pinching in foraminal space. Waited several years until function was being affected. Pre-surgery, ,y pain was predominantly in the location of the bad disc, on the left side of my neck. However, awakening from surgery, I noticed pain on the back right side of my neck, which is still present. I am told the paraspinal muscles, scalenes, among others, are still very tight and adjusting to the new physics post-surgery. I have had trigger point injection and am still taking (per pain management) tylenol, gabapentin, tizanidine (originally flexeril, switched by pain management due to upper trapezius pain on R), and celecoxib as an anti-inflammatory. It has been 11 months, I've been to PT, am limited in neck stretching due to physical constraints of the fusion, so most of what I have been getting is manual therapy. I will receive another trigger point injection. The switch from the muscle relaxant to the anti-spasmodic helped the trapezius pain, but made occipital pain and behind-the-ear (presumably at muscle attachment points) pain begin or worsen. I've been told 12-15 months can be required with some patients. I have a history of breast cancer and have had a mastectomy with reconstruction involving implants placed underneath my pectorals. I have had shoulder issues since that time (2017, final surgery for the reconstruction was 2018), also had aggressive chemo and radiation. I am wondering if anyone else has experienced this persistent pain after a cervical fusion and has any advice. Thank you.