Terry it is definitely frustrating. The good thing about my situation is I have a great BDE HQ team on the full time side that give me the opportunity to focus on my medical stuff when I need to but I never stop reading and researching to stay on top of the medical folks that make policy. I'm sitting at 17 years and fighting also.
For your situation the good I'm hearing from you is your in a non-deployable slot already. To me in my experience that is key as you don't have to find one and beat the S1's up to get you moved into one.
The one thing I would suggest you do if you haven't started is get to work on your COAD packet. Gather up some letters of recommendations from your CDR's, CSM's and anyone within your chain explaining that your needed and they are willing to keep you there in a non-deployable slot until you retire in order to get to 20 years. There are some others on here that have been down that road and can provide some feedback as well. Your PEBLO has the checklist of what is needed to build the COAD packet. When the DA 199 comes in there's only a 10 day period to get things turned back in to your PEBLO so having those memos ahead of time will help.
I have 8 letters currently from my current BDE CO as well as past Commanders and CSM's. this position I am in is an HRC directed move from May of last year reported Feb 2017, so I am hoping they will see that. My BDE CO changes out this month will that affect me being he will no longer be here?