First thing to do: Change counselors. It’s perfectly OK, allowed, and free. Yours is clearly incompetent.
(imagine someone telling a person in a wheelchair they’ll have to retake the track and field unit until they can run… That’s how cruel, ignorant, and offensive what your counselor said was.)
Second, is there a resource center on campus for disabilities, a support center, an office…? That’s where you should go ask about dyscalculia.