Have been having pressure in right side of head behind ear for 2 months with dizziness and stiff neck on that side. ct w/o contast?

Scan, yes: Because you are young the statistics shift toward less serious problems. However, a lesion of some type involving the mastoid or skull base near the mastoid might give you these symptoms. So, yes; you should have scan. Type of scan questionable. For bone CT is best. For other structure MR is best. Talk to your doctor. Contrast helps but we avoid in some conditions.