Checkup and Tamoxifen

Hi Ladies and Gentlemen,
I would love your opinion on a few things. I had posted before about having some aches and pains and some edema in my legs. Recently I have had Had some slight lightheadedness. I did bloodwork yesterday which was totally normal and also showed I was not in menapause. Next step to my gyno to talk about shutting down my ovaries or a hysterectomy. He took me off tamoxifen because he feels some of my tiredness and edema is caused by that. I know its not common to be er/pr pos and her+++ but has anyone else had bad reactions to tamoxifen? He said he will be putting me on either arimidex or femera! Then we talked about my dizziness and he didnt feel like it was due to any metastic disease but he said to make sure we are going to do a brain mri. That made me happy because of all the recent conversations we have had in here. My mother died of metastic brain cancer so this absolutely scares me so badly. I just wanted your opinions on the tamoxifen because it makes me nervous to not be taking anything while getting the ovaries shutdown, and about the reactions to it. Do you also think he is on the right track with the brain mri? Thankssssss so much for all your help!!