The search for the right answer is the enemy of art.
Marketing is about spreading ideas, and spreading ideas is the single most important output of our civilization.
Relying too much on proof distracts you from the real mission–which is emotional connection.
Take a chance on your own abilities clearly, neither exaggerating them nor under-assessing them.
If there was ever a moment to follow your passion and do work that matters, this is it.
Alas, there isn't a pain-free way to achieve your goals.