Suggest Remedy For Shooting Pain In Arm And Elbow Due To Having Double Joints

I am double jointed and previously my shoulders used to semi-dislocate a lot while doing sports. I now have my a-level examinations fast approaching and i have a really bad pain in my right elbow, it has slowed my writing down and sometimes i get a shooting pain down my arm to my hand, do you think i am allowed to apply for extra time in exams, if so do you know how i go about doing it?
Thankyou