Dizziness and swollen lymph nodes

I am a 30 year old female with no prior medical conditions or surgeries.  At the time of this writing the date is October 27, 2013 At the end of July I begin having dizzy spells. Not wild spinning vertigo and not as if I am about to lose consciousness either.  It is mildly annoying but sometimes worsens to where it interferes with my daily activities.I would describe it as a cross between light headedness and mild vertigo. I can't think of any triggers for this but usually once I begin feeling this way it continues until I go to sleep and wake up the following morning. I don't have it every day and so far I have seen no pattern. The only thing that makes me feel better is laying down and closing my eyes. My PCP ordered a lab workup, chest x-ray, EKG, and a CT scan.Everything on those diagnostics showed nothing unusual. I saw an ENT and a Neurologist. Neither could find the cause of my dizziness. Towards the last week of SeptemberI started experiencing discomfort of the armpit ,moving down the side of my breast. It was not at the time what I would call pain. After about two weeks of that I returned to my PCP and She told me she found a swollen lymph node in my armpit and another something along the top of my breast right below my armpit and she thought was a swollen lymph node as well. I was told it was probably nothing to worry about but she ordered a mammogram and  ultrasound to ease my mind. As of writing this I have not had them but they are scheduled for three days from now. I also received a flu shot at this visit. About three days later I begin to feel terrible… the armpit discomfort was now pain. I hurt all over and had a stiff neck.  I was not running a fever. This was a Sunday so I went into the ER. The doctor on call examined me and found additional swollen lymph nodes : one behind my ear, one under my chin, one in my neck, one down near my groin, and the opposite armpit node was swollen as well I experienced abdominal pain right below my ribcage on the right side as well. Once again I had blood work done and a chest x-ray. Once again I was told that everything looked normal and I most likely had some sort of “viral infection”.  It was thought that perhaps the flu shot had aggravated whatever I had. It has now been  four days and I feel much better, but the dizziness continues and I have to wonder about the possible connection between the dizziness and the swollen lymph nodes.  I followed up with my PCP and asked  for an HIV test and I should receive those results within the next day or so. All I know is that before this all started in  July I felt fine but ever since I have felt terrible and I would just like to know what’s causing this.