I didn't gain weight. My attitude was I would rather have pain or even disability (bones) than be dead. But again, joint pain improved with exercise longer than 20 minutes .

Tamoxifen and AI's have entirely different mechanisms of course so gaining weight on Tamoxifen wouldn't be relevant to your experience with an AI.

I would first say I was in my 30s when I took it, and I had a surgical oopherectomy at the same time. Although I did not gain weight on tamoxifen. I did have a lot of changes starting at that time. My skin started to age, my hair started to change texture. Essentially I started the normal aging process of a post menopausal woman. I just noticed it more because it happened earlier, and frankly faster. I started gaining weight when I had an accident and got pretty de-conditioned as a result. It has been a stubborn problem every since.
Have you felt that the pandemic has affected your activity levels over the last year? Have you seen a skin care specialist about your skin?