Has anyone tried low dose Tamoxifen?

I was diagnosed with Grade 2 DCIS in January. Had a lumpectomy on January 29th and the margins were clear. The tumor was 4.2 mm with necrosis. I elected not to have radiation. I'm also very reluctant to take Tamoxifen despite the urging of the nurse oncologist. She said that using the Sloan Kettering calculator that my risks for a return cancer were about 20% in the next 10 years if I do nothing. I understand that 50% of these returns can be invasive - and that the risk goes up after 10 years (I'm going on 57) and that the risk of getting any type of new breast cancer is higher. My logical mind says, "Why not try the Tamoxifen and see if I have any bad side effects before deciding not to take it?" I have the prescription sitting in front of me but I simply cannot compel myself to take one pill, knowing the potential side effects. I'm afraid the drug will make worse the menopausal symptoms I'm already struggling with (a bit of weight gain, some hot flashes, lower sex drive, some loss of sexual sensation, harder time falling and staying asleep) despite regularly exercising and good diet throughout most of my life - and also despite the fact that my estrogen levels say I haven't even reached menopause.

I read about the study on low dose Tamoxifen study and it sounds very compelling. I think I could actually wrap my head around taking a low 5mm dose. When I brought it up with my nurse oncologist, she said that there is no low dose prescription. But why not simply cut the pill in quarters? I read that in the study, some women took 10mm every other day and that seemed to work just as well. Has anyone tried this? From what I read, the suggested 20mm dose may be arbitrary and the drug is so cheap, there's no motivation to manufacture a lower dosage pill.