Hello Welcome in H.C.M. for your query. I read your query carefully and after considering all about your symptoms it appears as your upper cervical or jugulodiagestric lymph node is enlarged and became palpable. Since this lump is painless therefore it is not an acute pathology. Either you are having any chronic inflammatory lesion in your nose, sinuses, oral cavity & teeth, pharynx, larynx and submandibular salivary gland or it may be any chronic disease of lymph node itself. To confirm the etiology of lump you have to do very simple investigation i.e. FNAC from lump. This will disclose the real disease for this lump. Regards.