It could be lack of sleep, cloudy weather, indigestion, lot of time staring at a screen, dehydration....

Because your shoulders are up to your earlobes due to stress. (…and relax…) Get someone to give you a massage.

Maybe you're not drinking enough water?

...I... I don't even know where the base of the head is.

Low sex inactivity.

Probably a headache caused by stiffened muscles of the neck?

I've googled it, you have a brain tumour.

I need to read these answers because I STG sometimes I get up and it just feels like my head is going to snap off

Could be a tension headache 👨‍⚕️..

Your brain is too heavy

High screen brightness in a dark room