oral sex

does anyone else have issues with giving head? everytime i deep throat, my tonsils get red, swollen and get white patches on them for at least a week or two. I went to the Dr. and no one has an explanation besides the fact that my caves may be big and collect bacteria but if that was the case wouldn’t food get stuck as well? Also, my tonsils are naturally bigger than most people. I’ve heard so many things like being allergic to pre cum, but idk. It’s literally only when I deep throat, if I do it regularly nothing really happens