The only thing I came across to get beyond the 12-year eligibility period for VR&E is having a serious employment handicap.
The VA defines this as, "Having an SEH means your service-connected disability significantly limits your ability to prepare for, obtain, and maintain suitable employment (a job that doesn’t make your disability worse; is stable; and matches your abilities, aptitudes, and interests)."
I picked up on your 100% T&P status. It's possible that at least one or more of your conditions are significant enough to be considered a serious employment handicap, potentially requiring retraining for you to return to work.
So, it looks like there's a way. It's only a matter of whether you can make a case for it with a VR&E counselor.
Learn about eligibility requirements for Veteran Readiness and Employment (VR&E)—formerly called Vocational Rehabilitation and Employment. If you’re a service member or Veteran and have a disability that was caused—or made worse—by your active-duty service and that limits your ability to work or...
www.va.gov