hello dear. welcome to HealthCareMagic.com, thanks for asking here. I have understood your queries. I m sorry about your condition right now. but before, may I know do you have allergic history in family? how old are you? did you use another medicine together along with benadryl? do you have another chronic medical condition? Benadryl is an antihistamine contains diphenhidramine HCl, used to relieve allergic reactions such as sneezing, hives, itching, skin rash, allergic rhinitis like runny nose and watery eyes. beside that, it s also used to prevent nausea, vomiting and dizziness caused by motion sickness, to help you relax and induce sleepiness, and to treat certain symptoms of Parkinson s disease. many side effects can happen while on benadryl since it works in brain, the most common are drowsiness, dizziness, constipation, stomach upset, blurred vision, unsteadiness, headache, attention disturbance, dry mouth/nose/throat and fatigue. the less common effects such as abnormal sensation (tingling, numbness, etc), muscle weakness/twitching, vertigo, neuritis, psycho-motor impairment. I thought you may have allergic to diphenhidramine. even tough very serious allergic reaction to this drug is rare. the symptoms of a serious allergic reaction to benadryl include severe rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, and trouble breathing. these were like the complains you mentioned above. I suggest you to meet your local doctor to seek certainty of diagnosis and treatment. I hope these can be useful to answer your queries. hope you get well soon. if you have another things to be discussed, please feel free to ask me in HCM. take care. best regards, dr. Asti Yuliadha