I Have Had Symptoms Of A Cold For Nearly 3

I have had symptoms of a cold for nearly 3 weeks, the most difficult thing has been a very sore throat, which has caused hoarseness. I have had a high temperature, headaches, blurred vision (for half an hour) and the glands at the top of my neck (just under my chin) are swollen and feel sore. I went to the doctors four days ago and was prescribed antibiotics even though I was told my chest was clear. But 3 days ago, I noticed another lump on the side of my neck - it does not hurt but it does seem to have gotten bigger - should I return to the doctor?