I took Tamoxifen from 2000-2005. I gained a little weight, slowly, and I liked to blame the tamoxifen but it may well have been diet related too. I had no real side effects to speak of ad was thrilled and fortunate to have it in my arsenal to keep the fight going. I was in my early 30's at the time and found it created no obstacles. However, this all varies widely based on your age and just your on personal tolerance or reaction to it. Age comes into play as they said those closer to menopause age had a harder time with hotflashes. I had none.
If I were giving out advice, I'd encourage you to take it....and discontinue if the side effects become too intolerable.