Selenium is best as selenium methionine; Both NOW food and Swansons have a good one.
I wouldnt avoid everything because of estrogen; .
It is more important IMO to adress the digestion, adrenals, thyroid and the other endocrine organs; they make the hormones work, they balance the stuff.
No I am not a vegetarian anymore. I found out along the way that it was not worth it; though I like the idea.
But I chose my food with care and make most from scratch; still do a lot of fruit and vegetables.
If you cannot digest meat/proteins it may be that you lack pepsin and HCL. A simple way to find out is to eat beets (raw, red) if your urine colors red it is a problem on top of your digestion/ stomach acid.
I had this a lot, this was my weakest point.