I've been having dizzy spells ( two bad ones). had an mri done. no stroke issues. deep breathing helps after the spell. could it be allergic reaction?

Diizzy: there are many causes including eye, ear, neck, migraines. Start by haviing a good check up with your doctor. If normla then see a neurologist

Dizzy: Given the provided description it is more likely than not that your symptoms are not due to an allergy; you may have a serious cardiac issue or cardiopulmonary issue underlying that needs to be evaluated and treated. Get this attended to ASAP