It isn’t impossible to put yourself in someone else’s shoes. You will always see everything from your point of view, no matter whose shoes you put your feet in.
This is a good thing. Each of us has a unique perspective, based on our life experience, circumstances, background… no one has the same perspective as anyone else, which means none of us will ever write the same and none of us will ever create the same characters. It also means there will always be some of you in every character you write. And that can be pretty scary, but if you embrace that concept it can help you write believable characters.
Find the humanity in them, find the complexities, find the good that balances the bad. No hero or villain will ever be one or the other, we all believe in ourselves and that whatever we’re doing is the right thing to do. Even the bad guys.
Being a writer is exposing, it makes you vulnerable, and your characters should feel that too. If you feel like you’re putting your deepest secrets on the page for the whole world to read, you’re doing it right.