Tamoxifen better for 10 years?

Hi everyone, I am 66 years old and after HER2 and oestrogen positive diagnosis in October 2012, I had a mastecomy, two lymph nodes removed, no cancer cells in them, 3 months of chemo and finished herceptin in January this year. My oncologist originally told me 5 years for Tamoxifen, but has since told me he wants me to stay on it for 10 as I have had a hysterectomy years ago, and I am a good candidate to take it for the long term. I am constantly feeling hot, to the extent my husband of 44 years, has moved to the spare room as I am throwing the bed clothes off me, onto him during the night. I have bad mood swings, even panic attacks, which I found meditation helps. Mostly, I seem to get confused easily, and find it hard to concentrate or focus on things for very long. I have always been an avid reader, but can't focus enough to pick up a book these days. Not sure whether the tamoxifen is to blame, or it is just the way I am feeling. Someone mentioned the lack of libido, and I know what she means.....what libido? Would be interested in hearing from others having similar problems, and what they do to ease them. I also get very itchy when I get hot, like prickly heat. Bye now Jill