If those were her expectations (and I don't think they are), I would say it doesn't make you a bad person not to be able to or want to live up to them. Even the vows themselves state you're making them "until death." That doesn't mean you didn't love her or take anything away from the time you spent living up to those vows while you had each other. It doesn't even mean you won't be reunited when you get to where she is. It just means you are no longer obligated to her in the same way you were when she was alive.