Hello
I have constant headaches from eye styrain but most importantly anxiety. Its a tight shoulder, neck, clenched jaw thing and a tight band around my head.
This is classic anxiety and remember you are so used to feeling this tightness you wouldn't even notice your body being clenched and tight. I bet if you rub the back of your neck or shoulders firmly you will find it stiff and sore which will prove its anxciety.
Honestly mate don't worry - with a brain tumour you would have much worse symptoms than this
You are ok !
Love and a big hug
SUE xxx