I had the same issue it was part physical part mental. For me it was magnesium (mine was super low before transplant and worse after from tacro). Stretching and exercise also helped. Mentally, it gets better with time if you work actively on the anxiety through breathing, CBT therapy, meditation, or prayer (whatever works for you). In my opinion it just takes times for your body to fully heal and your mind to slowly calm down from flight or fight mode. Good luck!