I am so sorry you have had to go through all of that!!
When I know my friend is going through something or is healing from something and I ask how they are, I expect details. I don't like responses like, "good," when I know they aren't. However, I am not going to force them to talk if they don't want to. If people ask how I am, I would respond like you. I don't understand people asking that question and not wanting an honest answer. I think your approach of allowing them to ask for more details before giving them all is a good way to go about it. It's just a shame that is something you have to do.
I hope you feel better soon! You can always vent on Medium. We allow all the details here lol!