I will DM you soon to talk about various things, you can also DM me anytime. Anyway, i think in Islam the use of estrogen would be allowed if the person's health was really in danger. We're even told that if you're about to starve to death and find a human corpse, you're obligated to eat it and survive. And at the same time, if you have a sickness and you want to embrace death and not get treated, you're free to do so, and it'd not be considered a suicide, as you're not responsible for the disease occurrence and it's not really an environmental threat if you can spot my intentions
For transgenders, i will be clear with you. There are two types of transgenders in Islam. Firstly, those who are born without a clear gender - Hermaphrodites for instance - are allowed to see which gender they prefer and then transition to said gender. For the other cases though, it depends. They generally should consult specialists, as i saw in a fatwa before, since some cases can be unique. But generally, if you're a functioning male or a female with no issues, then transitioning would be considered a huge sin, as it changes God's original creation without correcting a mistake. You might find that conflicting as a transgender person, but i'm just being honest with you as i don't like twisting my beliefs and sugarcoating them in order to make them more appealing to others, and i think you're owed honesty in our discussion since we've been in more than one so far