Could My Hives, Blurry Vision, And Fainting Triggered By Heat Or Exertion Be Cholinergic Urticaria, Despite My Doctor Attributing It To Weight?

Since I was about 10 years old, everytime I would get hot, exercise, or get mad I would break out into hives. I went to my doctor a few times and he said the reason for it was because I was over weight, but says that about everything even if I have a cold. It eventually got to the point when whenever I got the hives I would pass out depending on how hot I felt. First I get hives, then my vision goes blurry and I pass out. Could there be a possibility that I have cholinergic urticaria?