What Causes Stiffness In Neck With A Lump And Headaches?

I can feel a slight lump on the right side of my neck as well as some stiffness in my neck accompanied with headaches over the past 3 days which sometimes seems to be localized to the back of my eyeballs. I've only noticed the lump today. I'm 22 years old and have been taking paracetamol tablets for the past 3 days in the evening as the pain becomes unbearable but it returns every morning with neck stiffness.