Am I the only one regretting buying that famous serum?

I excitedly bought that vitamin C serum that everyone can't stop praising, but it seriously gave me tiny little bumps on my face. I mean, can a product have such a big effect? Did no one else have side effects? I really don't get it. I wonder what those with sensitive skin like mine use. Please give me some advice so that money doesn’t go to waste; suggest something.