Men aren't the enemy of feminism and equality. It doesn't matter what any man has done to you, being a bigot doesn't fix it.
There are real problems in the world that benefit from attention. And most people prefer to waste their energy being mad at made up shit designed to make them hate their neighbors.
As a trans person yes, absolutely the anguish we feel for not being comfortable in our bodies is 100% mental illness. And people get upset because we see mental illness as a bad thing, a personal failure, instead of a condition to be treated.
Doctors have decided that transitioning, while it doesn't fix the problem of people not being born as their preferred gender, is much healthier treatment for the individual and society so that we can try to live happier lives where we get to feel as comfortable as cis people naturally feel.