questionable symptoms

I have a lump in the back of my neck on left side, not visible but palpable, along with that I have an new onset of wrist joint pain in left hand and joint pain in left ankle. I also have numbness type tingling in left arm that seems to come and go, sometimes it feels like I have a rubber band around it somewhere. I often feel like I have a fever even though I do not, just a general warm feeling in my head and neck. The doctor put me on an antibiotic 5 days ago but it has made no difference and I'm getting very nervous. I have experienced light sweating a night a handful of times but nothing alarming and lately I seem to have heart palpitations more frequently, Please offer me some advice and share any similar stories.