What Does Hard And Sore Lump Above The Collarbone Suggest?

Hello. I m a 45 year old female in healthy condition. I am concerned and have a quick questions. II was rubbing my right collarbone and found a lump above the collarbone the size of a marble. It is hard and can be moved around a bit. initially it did not hurt to touch but since I ve been touching it it s now sore. I have been having some hot flashes lately and getting hot at night. Also, my neck and my back shoulders have been sore lately. can you please give me some advice on how to proceed with precautions. Thank you.