20yr old. stressed and worried and now have aching neck and headache. and beginning to think it's a brain tumor. is it just anxiety? two weeks started

Anxiety is my bet: Anxiety is a prime suspect for almost all symptoms - especially the "soft" ones w/out known lab tests or imaging. Here's a great Dx Tool! If the symptom can change based on distraction or focus - it's probably anxiety. Fractures, tumors, viruses, etc. do not come or go in response to a phone call, great song, annoying chatter. If it is always there, see a doctor - but brain tumors are rare.