I have been taking indol 3 carbinole since March.Like you I was frustrated with the side effects and when I heard about I3C I really felt that I did have a choice. I first heard of it in France from a lady who has been taking it for ten years. I see a naturopath who monitors my oestrogen levels through a saliva test. I think you need a practitioner to order I3C. i get mine from metagenics. I have found this Uk website helpful on I3C
http://www.canceractive.com/cancer-active-page-link.aspx?n=1417
If you put I3C in the search function there are more articles on research. I also met an American nurse who had attended a conference on I3C and told me that I had made the best choice. I have also eliminated red meat and chicken, occasionally I eat duck.
I feel very comfortable with my choice as I know that if I don't feel well it is not caused by Tamoxifen, however who knows what chemo does to our bodies!
Another interesting article on Xenoestrogens - chemical hormones in your daily lives
http://www.canceractive.com/cancer-active-page-link.aspx?n=3148
I think we just need to be comfortable with our decisions - do what feels right for us, there is no right or wrong and ultimately we can't control what our bodies do, only help them to stay healthy as much as we can.