Do not worry, you do not have cancer from the symptoms you have described. You seem to have an infective condition of ear most probably chronic suppurative otitis media
which responds to antibiotics. There os usually a perforation in ear drum which usually heals if it is small or if large can be corrected with surgery. Just take antibiotics, oral decongestants and antibiotic ear drops for few days and when your appointment date comes, consult your ENT. Take care.