NHS pension

HI I am not sure if I have posted this in the correct place but I hope someone will be able to advise me or point me in the right direction.  I applied for my NHS pension on sickness grounds back in 2004 and was refused.  My Consultant at the time said that he was worried I did not get it because one of the questions he had to answer was, did he think there might be a cure found in the next 17 years (which was the amount of time I had left to work before official retirement) and he answered possibly.   Sadly a cure has not been found.  I went into hospital for treatment at that time every four weeks as an inpatient for seven days but now and have done for the past 11 years go in weekly for treatment, 52 weeks a year.   I have also just found out today that my GP has had the wrong diagnosis on my NHS records since 2003!  The diagnosis they have for me is nothing compared to what I have and is definitely not something you could reitre on sickness grounds for.  It is the NHS code I am talking about but no one at the surgery has ever noticed it depsote receiving 52 letters per year from my hospital Consultant with the correct diagnosis emblazoned across the top of each letter.  I found this out becuase I am elibigible for the Covid vaccine as high risk but my GP had me in category 8, in other words all people aged 55 plus despite my health problems.  Thankfully I am getting that sorted out but if my NHS medical records have had a wrong disgnosis in all of this time I really wonder now if that affected their decision not to give me my pension on sickness grounds and also the fact that I am 18 years down the line from that refusal and no nearer any cure, in fact my Consultant now openly states there is no cure, surely this proves that their decision was wrong?.

My questions are, Is it worth me attempting to get the decision changed and how would I even start the process?

Any help would be very much appreciated, Many thanks!