Why isn't my cold going away?

ok so is been about a week and i have a cold when it started out i sneezed and had nasal congestion and no fever and now its been a week and my sneezing is going a my head is congested i think i don't really know and my nose is stuffed i can't breathe out of one side of my nose. I have been taking medicine but it barley does anything other thank clear my nose. What should i do im not sick and my head doesn't hurt it never did. My head is dizzy all the time.