Lump on neck for more than a year: what can it be?

My question is this: I have had this lump on the right side of my neck for some time now (over a year) and I have had feelings of fullness in my head (pressure) Two cat scans and an MRI of neck and head and an MRA of head showed normal. I have been to the er room for this on one occasion because the pressure was very bad and I felt I needed medical attention right away. After I was seen and blood work done it showed that my Neutropphils count was high(79.2) range= 43.0 - 72.0% / Lymphcytes Low (14.2) range = 18.0 - 43.0%. My segs for the Differential Manual were high 78 range = 25 - 62% and lymphs low 15 range= 20 - 52%. I was also told the lumpo in my neck was a swollen/infected lymph node (2 doctors confirmed this) The ER doctor suggested I bring this to my doctors attention, which I did the next day, and she told me there was nothing wrong with me except stress due to the death of my mother (died of lung cancer in March 2006 - I was at the doctors for this in June 2006). So nothing was done except that she kept me on Ativan for stress, which did nothing for the feelings I get on the same side of my head that the lump is on. Over the past several months I have been getting night sweats, feelings of just not feeling good (always asking "do I have a fever?" and feeling hot and cold- wake up with night sweats which are not constant but enough to make me aware there is something going on) - I am just getting over a sinus infection that took two weeks to clear the infection but I still have a cough and achey feelings (like the flu) I had a chest x-ray which was normal. I did some research on the low and high counts of the blood and the swollen lymph node in my neck and it all led me to Hodgkins/Non Hodgkins disease. I am in need of some advice - Should I seek a second opinion from another doctor or wait until my symptoms get worse? HELP!