DVLA and Cerebral Palsy

i am just after some advice I have cerebral Palsy. I have been driving for 17 years and use hand controls to enable me to drive, I informed DVLA of this in 2002 when I passed my test I told them of my condition and my hand controls  I have an exemplary driving record and have had no incidents (touch wood) I never go to the GP and am not on any medication. At the beginning of September the DVLA sent me a letter saying my photo needed updating on my license, so I sent off the D1 form.

a Month later I received a letter asking me to fill in a G1, as I had declared a medical condition, I rang up the DVLA medical unit and stated that I couldn’t understand why I had received this letter I had no new medical conditions and that I had no deterioration in my Cerebral Palsy since I passed my test. they said they had no record of my cerebral palsy and that I had to fill in a B1 as well. Then 3 weeks after that I received a letter saying they were sending me for a medical examination with my GP. I rang them upset all I wanted was a new photo license and it has escalated to this. I asked them to then look  back in to there records they then found my 2002 cerebral palsy declaration and the fact that use hand controls, but said that I still have to go to the medical because the codes on the back of driving licence  state that I wear glasses and drive an automatic but not that I use hand controls., 

i feel as if I am being discriminated against as if an able-bodied person had applied for a photo license they would not be subjected to this level of stress and anxiety, and told to undergo a medical examination or have there licence revoked 

my car is my lifeline and my independence and I am frightened that it will be taken away from me. Can anyone offer any advice or has anyone been in a similar position. I never go to the doctors and am worried my condition will not be understood.