Giving up on hormone therapy

I just turned 40 and stopped taking Tamoxifen after being on it for about 9 months. My risk of recurrence is low and the benefit of tamoxifen doesn’t seem to be worth the many side effects I was experiencing (fatigue, hot flashes, insomnia, joint pain, moodiness).

I’ve been off tam for about a month now, and I do feel a bit better, but I’ve always struggled with depression, anxiety, bad sleep, adhd, and low energy (even though I’m very active), so I can’t say “I feel great now!” I don’t know what to do.

My internal medicine doc said she tells women every day that their breast cancer from many years ago is back and metastatic, so she doesn’t want me to take the decision lightly.

Of course I’m worried about recurrence, so I’m considering trying out a lower dose to see if the side effects are more manageable.

But, I have not found any studies about the long term effectiveness of tamoxifen treatment for women in our age range. Am I missing something?