It sounds like a combination of things, some treatment related. Has any doctor suggested it may be Benign paroxysmal positional vertigo (BPPV)? Here is a link that describes many of your symptoms:
http://www.mayoclinic.com/health/vertigo/DS00534
I worked through chemo and beyond and thought I was doing quite well - a little slower than normal, but noticeable to only those closest to me. It really hit home how much this really did effect me when I couldn't remember the exact date of my son's birthday - very unsettling. Another instance was not remembering the last name of my aunt, whom I saw constantly growing up. I actually had to go through my address book page by page until I found it - YIKES! Now, 2+years out from treatment I still feel a little woozy at times. I just had a brain MRI and it was fine.
Keep looking for answers. Maybe throw an ENT into the mix to get another opinion.
Best of luck to you!
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Gerri
Dx: 11/23/05, Lumpectomy 12/12/05
Tumor 2.2 cm, Stage II, Grade 3, Sentinel Node biopsy negative
ER+ (30%) /PR+ (50%), HER2+++
AC X 4 dose dense, Taxol X 4 dose dense
Herceptin started with 2nd Taxol, given weekly until chemo done
then given every 3 weeks for one year ending on March 16, 2007
Radiation 30 treatments
Tamoxifen - 2 yrs (pre-menopausal)
May 2008 - Feb 2012 Femara
Aug 2008 - Feb 2012 Zometa every 6 months
March 2012 - Stop Femara, now Evista for bone strengthening
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Enjoy the little things, for one day you may look
back and realize they were the big things.
- Robert Brault