I don't want to write up an walkthru or anything but I have gotten all the endings and I can probably give you a hint if say what's got you stuck.
Not the OP but if I were to ask anything of you, fellow commenter, it would simply be this: what must one actually do to start each route?
If I had a clear guide of how to start each route properly, I'd have much more tolerance for exploration and testing. You needn't provide this, of course, but if you do feel like doing so, you would have my thanks.
I'll answer this vaguely as I'm kind of onboard with figuring out as much as you can solo but can give more concrete answers later if needed.
All of the paths are initially set in Act1(asylum). Depending on how you play it out it sets you on the chosen path. You can still fail that path if you don't play out the following acts correctly, which can take some experimentation.
However, there is a secret hidden in Act1 that once triggered will let you know if you are still on track in the following acts. You'll know it when you've found the secret, it's not anything vague.