I am 22 years old, about 5'6", and weigh 120, no major health issues in my past, and rarely even get colds. About a week ago, I noticed there is a lump in the middle of the left side of the back my neck. For the past few weeks, I have been getting pretty bad dizzy spells, in which case 1/3 times the hearing in my left ear becomes muffled, this whole process takes only a few minutes. I also have been getting light headed often, and I'm not one to get light headed or dizzy. The lump is visible and is clearly there to the touch, and when you feel it underneath, it's hard. It also hurts to move my neck, especially to the right and in fast movements. I have gotten blood work done, but the tests came back normal. What might be going on?