Hard lump on back of neck with other symptoms

I have a hard lump on the back of my neck just above the hairline. I've had it for a while, but it sometimes really aches now, and I've noticed a smaller hard nodule about an inch below it. I have neck pain sometimes, and incredibly troublesome tinnitus on that side, also dizzy spells and headaches. I get tingly sensations in my hand.
Any suggestions?