Feel like my head is spinning

I had a single mastectomy (my choice) in Nov 2015. Three weeks later I was back in hospital having all my underarm lymph nodes removed as the sentinel node had tested positive. Fortunately it was only in the sentinel node and not the others. My cancer was 2.5cm and looked like a black goldfish with googly eyes lol. It was ER+ and weak PR+ so I had 4 x 3weekly doses of chemo. I didn't have to have radiology as the breast was totally gone and the specialist didn't see the need for it. Side effect of having no lymph nodes in the arm is lymphedema which is a swelling that comes and goes but its manageable with a sleeve and gauntlet when needed. I am on Tamoxifen for at least 2yrs. I am 54 years old.