319pj:
Your problem is that you are too qualified or else you are on the wrong aeroplane. This is nothing new when it comes to finding a new job. Can you just imagine an existing airline offering you a job as a direct-entry captain when they already have many senior first officers who have been with the company for many years?
I have been in this situation a couple of times in the past. You simply cannot afford to be the most junior pilot in an existing company at your age (even if it is BA).
What you need to do is to find a new start-up company who need your experience right at the beginning and who want you with your experience as a captain.
I managed to do this (after a couple of false starts) and ended up with a good financial result when I retired and I never ever had to go back into the right seat.
There were times that it wasn't easy but I achieved two huge ambitions in my life; I never had to work in the Kingdom and I never had to work for BA.