Teach me, Obi Wan. You're our only hope.
Seriously, I'm relatively handy with power tools, and am usually pretty ambitious and confident with projects. But I just can't seem to get over my fear and just redo our bathroom (and kitchen, and basement, and....). It's just too intimidating. I need someone who knows what they're doing to do a major project with me to give me confidence.
Seriously you just need to lay out a step by step plan and then jump in with both feet. If you keep thinking about the project as a whole it feels really overwhelming and impossible but each step feels really easy. Plus once you rip the room out not having your master bath provides lots of motivation to get it back together .
edit: also buy lots of beer and when you get frustrated put your tools and shit down and go have one (or ten depending on how frustrated you are, just keep drinking them until you aren't frustrated any more.).