Welcome to Healing Well. Please do not worry, I doubt very much that this is a tumour as you would have experienced many other symptoms by now and had a diagnosis before the headache appeared.
If this continues however, do get a Doctors opinion as this sounds that the pain is around your trigeminal nerve, but it sounds more like a tension headache to me, as it is persistent and you are naturally somewhat concerned.
However I am not a Doc and cannot diagnose, so if in doubt please get it checked out.
Co-Moderator of the Migraine/Headache Forum
DX: Hemicrania Continua, Chronic Migraine, IBS, Allergic Rhinitis and Heart Murmur
Meds: Imigran Injections, High Flow Oxygen, Mebeverine, Lansoprazole, Nasonex and Clarityn