Lip numbness, localized swelling, severe metallic taste, light tooth loosening, do i have cancer?

Not likely: Sounds mostly like an allergic reaction. While some chemotherapy agents can causes these types of side effects, if you do not already have cancer, then the above symptoms are far more likely to have a benign cause. If they persist check with your primary care doctor. Possible causes could be malnutrition, allergic reaction, thyroid disorder, dietary causes.