What Causes Multiple Movable, Painful Lumps On And Around The Neck?

i recently had one lump on the side of my neck (i ve had this for years) but then i found one on my collarbone, one on my chest and about 6 more on my neck over the past 6-ish months, most hurt, the ones that don t are move-able. i ve been increasingly tired, nausea and headaches as well as random chills and sweats. just found it really odd. i went to get an x-ray and they said everything looks fine. should i get a second opinion, or a CT scan of some sort? thanks. -anthony