Anascoria [uneven pupils] & doc just found a lump on my lower right neck on thyroid.

Well this is bittersweet.
A year ago I noticed something funny going on with my eye and looked in the mirror and saw that my right eye was extremely dilated.  I went to the ER as it was not just slightly dialated but very dialated.  I ended up having a panic attack right there so all they did was tell me to see a Opthmologist or Nuero and sent me home with xanax.  

Now a year later after seeing 3 different eyes docs.. 2 different Nueros... several GPs and a Nuero-Optomologist [and being unofficially diagnosed with Acid Reflux, Migranes (migraines) & Adies Pupil] I finally go to another docter [first time with insurance] and they find a lump on the right side of my neck.

Now some history about my Thyroid.
I was diagnosed with Hypothyroidism IN 5TH GRADE.  Yes VERY young.  I had a goiter and have lived with it since being diagnosed altho you would never know unless I told you.  My face gets puffed up all the time seemingly for no reason.. randomly I should say. My pupil stays slightly bigger all the time.. but so slightly the doctors brush it off and tell me I've always had it... I KNOW I HAVENT.  It is more defined in dim light.  And in times of stress or if I'm tired.. and then sometimes it's completely random.  I have migraines frequently.  I have hot/cold intolerance, I am tired all the time, I am very anxious and do have panic attacks although I am going through some things in my life that do contribute to that.  I am currently on 112 mcg of Synthroid a day.  It has been 6-11 months since my Thyroid has been checked.

Oh and I have boughts where I cannot breathe.  My neck feels tight when I swollow but this is NOT new.  I am mad that no doc has picked up on the LUMP ON THE RIGHT SIDE OF MY NECK ONLY ON TOP OF MY GOITER.  I mean seriously...

When I first went and saw the Nuero almost a year ago they thought I had a Pituary Tumor.  After an MRI/MRA without contrast they ruled that out.  Quote "unremarkable findings".  They also said it could be a tumor in the chest but nobody wanted to do a chest Xray.  Well, I had no insurance so no surprise there.  

Now after seeing this one GP who found the lump in my neck they sent me for Bloodwork that day.  Now I have to wait a wk to get results back but the head doctor told the under doctor to run a chest Xray and Thyroid ultrasound on me.  Although they said they did not want to schudle it until after they recieved the blood work back.

CAN A DOCTOR PLEASE TELL ME WHAT MY GP MIGHT BE THINKING?
DOES THIS SOUND CANCEROUS?

Didn't mean to sound angry in all caps but I really would like some help.. it is greatly appreciated.