How do you treat positional vertigo? its causing me to have major headaches and pain/heaviness on the back of my head and neck.

Confirm it first: Benign positional vertigo can cause significant symptoms (namely the sense of room spinning). It usually does not cause pain or headaches. I would get into see your primary or an ENT to ensure you have the right diagnosis.

Positional vertigo: If true positional vertigo then treatment with repositioning, also called epley maneuvers is very effective. Headache is not common with positional vertigo.