Head and Neck
Is your pillow height right for the way you sleep? Do you have poking head? Can you look the same distance around to your left versus your right?

These questions are important when thinking about the 'normal' resting position and range of motion in your neck.
If you have poor resting positions, for example your head pokes forward during the day or during the night, this will cause extra stress on your cervical vertebrae (the spine of your neck). Extra strain on your neck will make it very difficult to continuously hold up your heavy head, so you may find yourself subconsciously resting your head on your hands.
The range of motion that your head can 'normally' turn will be affected by how much neck range you use in daily living, and any past history of neck trauma. You will notice problems when one, or more, of the joints in one side of your neck stop moving smoothly. If joints or discs in your neck are not moving optimally, they can pinch on nerves causing headaches, pins and needles or numbness down your arm(s), weakness in your shoulders, etc.
A book called 'Treat your own neck' by Brian Mulligan is a great place to start helping yourself. By moving through your normal painfree range of neck motion then trying to stretch a tiny bit more, you can start to treat yourself and regain mobility.
Vertigo can be caused by salt crystals getting stuck on the hairs in your inner ear. The dix-hallpike maneuver can be instantly relieving. Book a private session if you would like me to perform this non-invasive treatment for you.