I CAN'T OPEN MY FINGERS when my wrist is curled up!!! (docs pls help I wanna play guitar pls)

(my right hand) When I fully extend my wrist, making it bend as far backward as I can, I lose the ability to open my fingers; it feels as though I don't have control over them. When my wrist is in a neutral position, I can open my fingers to a certain extent, but if I apply more pressure, my fingers start vibrating and eventually cause pain as the pressure builds up. I can only open my fingers completely when my wrist is fully bent inward but only my 4 fingers not my thumb my thumb only moves a little. Essentially, as I move my wrist from an inward to an outward position, I lose control of my fingers, and they curl up once my wrist is fully bent backward. The most weird part is that when my wrist is in the position in which I can't open my fingers, I could open them only if I apply pressure to the area from where my fingers start idk how to describe it basically the area in my pal from where the fingers are emerging, only when with the help of my other fingers I apply pressure in that area I am able to move my fingers which I couldn't do otherwise by my own, except my thumb, doesn't matter where I press I cannot make it open it, I can only wiggle it to a certain extent.

I have full sensation in all my fingers and can feel everything just as well as I do with my left hand. My grip strength is almost the same as my left hand my affected hand is my right hand also my dominant hand and I'm able to do all the things which don require my fingers to open up like writing painting, paying table tennis and badminton, I cannot play piano that well cuz theres only so much u can do with your left hand and 1 finger of your right, same goes with guitar, god I hope I could play guitar someday . I have had this condition since I was 12 years old (or possibly earlier, but I can't recall). Despite consulting top doctors over the past three years, they have been unable to diagnose my condition.