I never would have thought of being an empath as having a psychological problem, I always thought of it as a type of extra-sensory perception. Something we all have to varying degrees.
I agree that you would be wise to seek some type of help if it is causing you to be physically ill.
I wonder, since you don't seem to have any episodes when you are at school if it is because you are focused on so many other things. Friends, noises, teachers etc. Perhaps you could immerse yourself in some type of activity that would take your mind off an episode if one occurs that is particularly disturbing. Focus externally instead of internally. Whatever would work, calling a friend, listening to music, reading a book or magazine. Anything that would require your attention somewhere else.
I hadn't thought of how I learned to "shut off" when I find myself receiving input I would rather not have. I am still susceptible to being overwhelmed, but the episodes are rare.
Hope this helps