I've talked to enough people in other industries who have dealt with this situation, which has been affecting me lately, so I thought I'd ask.

How do you deal with when a boss keeps changing what the end goal of a project is? Especially when you are passionate about this technically challenging and risky project and communicate regularly with stakeholders, and your boss is far removed, says he/she changed mind when they woke up one morning, and don't realize or don't care how it might affect stakeholders. And also, how to deal with the frustration of all the time you spent planning, and not even understanding why things changed?

And perhaps finally, how do you keep it from affecting you outside of work?

My dad told me I just need to let it go, follow the boss, document it, and accept that the project may fail. He said I am too low in the organization to be the project "sponor," and I should not be defending the "right" way to do it. He said that is the job of the sponsor, and really there isn't any. Just people who attack how the project is going. So he said let it fail. I countered that my performance rating will be based on whether it succeeded, and saying a boss interfered won't fly. He countered and told me to find a new job (which I'm working on).