YosemiteSam,
In my opinion, you are! You should have been extended on orders. The doctor who diagnosed you should have initiated an MEB when s/he made the diagnosis.
I think you are entitled to INCAP pay.
You mentioned not having a final disposition from DES. Are you going through an MEB?
There are several ways to address this. You could pursue talking with your chain of command, the IG, perhaps a Congressional. You could also petition the
AF Board for Correction of Military Records (asking to correct your records to show you were never separated off of active duty; this should have the effect of capturing your back pay, too).
Bottom line, I think they are denying you your rights.
Please let us know any questions.