My husband's tumor & lymph node sound very similar - 4.7 cm tumor on base of tongue and large lymph node on neck. He had terrible pain, which he described as headache, prior to diagnosis. Took Norco for it. He is almost done with treatment, just one rads left to go, and that pain improved as the tumor shrunk. He hasn't complained of headache for a few weeks. His pain now is from mucositis and radiation dermatitis, which should start to heal soon. Now on fentanyl patch with oxy for breakthrough pain. He finds the patch doesn't make him feel drugged, like the oral meds do. Early on, MO said the head pain was likely from tumor pressing on a nerve.

Good luck with everything. Hang in there!