You haven't broken your children.
I'm many other cultures children of these age would share rooms with parents/other siblings. They still grow up capable of independent sleep. However, if it's not working for you, you are the parent and can change it. Lots of different approaches, pick one that works for you. Sticker chart? You just need to be really calm and consistent, they are old enough to explain to, and and little reward (sticker onthe chart or similar) when they do well with it.
My eldest still wanted taking to be toilet at that age. Particularly for poos - she liked to have someone read a story to her as she found them tricky. It was never an issue at preschool - because the loo was right next to the classroom that didn't feel as alone to her as going upstairs and she just didn't poo at school. She started taking herself with confidence when shewas 5. I never considered it to be a big deal if I'm honest.
Nappies at night is not a bit deal, and you've been given lots of suggestions. Again, it's not a problem! But as the parent if you think it's time for a change that is your choice. Pick a method you are happy with (you've been given several suggestions on this thread) and just be consistent and patient.
You're never going to break your children by being loving. Just pair it with calm, consistent boundaries that you adapt when you think its time.
(No, this is not always easy, and yes, I fall short of this! But just keep trying)