Go to a dermatologist, muy pronto.
Basal Cell Carcinoma is very treatable, the likelihood of death from that form of skin cancer is like 0.02%. Squamous Cell Carcinoma is slightly more serious, but still has a very high success rate from treatment. Malignant Melanoma is the scary one.
I've had two basal cell carcinomas removed, one on my elbow and one on my knee. There was nothing to it.