You're backtracking, that's all there is to it.
Yes we've had roles that are different, but generally when a role is that bizarre, it's because it's fake.
I believe you when you say you can protect yourself. But that is not a bodyguard.
That is what an sk or a commuter or kidnapper does.
Docs cannot protect th emselves because it's game breaking. It's a player that cannot be killed. Obviously as you say it weakens, however, that would effectively convince mafia to never target you, since there's a chance you will just block it. It is game breaking to allow a doc or bodyguard, to protect themselves.
I believe your power is real. It's just not a town bodyguard power.