What should I do if I dont like any college major?

Ive been through a few of them, I started in physics, went to econ, then econ and math, and now Im in mathematical sciences, but I totally hate what I am studying and I always have, thats why I switch around so much. I haven't done well in any of them either. now Its the end of my junior year and I feel like a failure because college is supposed to be where you find what you like and what you are good at and Ive done neither. I spend all my spare time researching inventions that I could create and market but so far, Ive come up with nothing and there is no major in that.