Where do i go im 16 about to have my gcse exams and i think im dislexic?

im 16 and im finishing school in less than 2 months but i think im dyslexic because i have always realy struggled with english but its seems to be getting worse when i was young my nan told me that i could barley wright and i was extremly absent minded and my grandad had to giveme extra english lessons everyday just so i could wright but i didnt know any of this until recently but i dont know what to do now because i only have a few months left but i also have 6 form and uni but i dont know if i need to be dianosed