I'm 64 years old and was diagnosed as hypogonadic (what your call andropause) about seven years ago.
I can tell you it's a pretty miserable condition. It leads to extreme lack of energy, a sort of living death. Even when well rested, if you sit down you will find yourself dozing off.
I started regular testosterone injections, but it had a bit of a paradoxical effect. There is any enzyme called aromatase, which is present in fat cells. It converts testosterone to estradiol. In effect I was getting a goodly dose of estrogen.
I can tell you a few things. Taking exogenous estrogen will eventually shut down your natural production of testosterone. That may take a few months or a few years. Stopping the estrogen may or may not allow testosterone production to return. The longer you are on estrogen and the stronger the dose, the less likely that testosterone production will resume.
To be healthy, you need both estrogen and testosterone. Healthy cis-women need and have some circulating testosterone.
In essence, after years of taking estrogen you will be, like me, hypogonadic and require regular supplementation of estrogen, testosterone or both.
I exist primarily on estrogen now, but still find that I need some testosterone to remain strong and healthy.
In summary, your ideas are correct. In an attempt to become a young woman, you may develop the symptoms of being an old man.
Randi