Suggest Treatment For Stiffness Of Neck And Lumps On The Head

Hi, My name is Mateusz. I m 29 years old and am relatively healthy and active. Just a few days ago, while I was working late, I began to notice that I had a stiff neck. I thought this was caused by me staying up late and working on my computer. The following day I noticed the same soreness as I slept and felt some pain / discomfort. Following this, I had my hair cut and felt great discomfort as the hairdresser washing my hair applied pressure to 3 locations that had lumps and suggested I see a doctor. These tree lumps are located on the back of my neck and along my head. They feel like the size of a dime and tend to provide some mild discomfort at night. I can feel them when I touch them and they are firm. I am going to schedule an appointment as I am concerned, but was hoping to get some insight as to what this might be?