Try not to feel guilty. It’s not like you are trying to take advantage of him by doing something sneaky, withdrawing and hiding money from mutual accounts and selling his stuff in secret or looking for his replacement. All you are doing is weighing options. He isn’t a child or disabled and he isn’t being abandoned. He is a grown man.

And I might be wrong but he doesn’t sound like a person you can amicably separate in the same household and peacefully discuss you considering divorce. I don’t see it’s happening. In those circumstances what you are doing is the only safe option