You simply lack the quantitative ability that students pursuing this career are required to have. It's not anything that anyone can hold against you. You just don't have what it takes, and you never will. Don't hold it against yourself -- it's just how you were born.
Might I suggest an alternative career in art history, as a CNA, as a surgical technologist, front desk receptionist... ?
Also, don't forget to consider a career as a fast-food chef; many of the corporate chains (e.g., McDonald's, Burger King) offer very attractive insurance and benefits packages. Plus, at least you'd be around a group of individuals whose intellectual capacities you can relate to.