Hello, and welcome!
I can relate, to some extent. Atrophy of my left leg, osteoarthritis, multi-level facet degeneration...the list goes on. I've also been in this system for more months than I care to count.
Evidence is your best friend. That's what I've had drilled into my head here, and it's the truth. Every month or two I would go to the medical records office at my MTF and have the latest electonic medical records printed up. Every time I had to carry around my own medical record I was scan copies of what things that had been written in it instead of on the computer. If you can get away with doing this at work, it saves a lot of time and money.
This way, if you wind up going to the formal board instead of being able to get it resolved through the formal board, you'll have plenty of evidence to show them for what you should be properly rated.
Good luck to you!