Really sore pulse on side of my neck. gets very painful?

Pulsating pain: If you have some growth (for lack of a better description) that is pulsating, seek immediate medical attention.

It's sore & pulses?: Get Thee to Emergencee. This could be an arteriovenous malformation or a fistular formation or an aneurysm which is banging up against a large nerve trunk or set of nerves causing the pain. This needs to be looked at sooner rather than later. Gotta make sure your blood pressure is good and get a fix on what this "sore pulse" is all about.