The Only Plan or The Plan B Dilemma

Hey Miss Awesome,

I wanted to ask your take on my situation:
I married an incredible man six years ago and was encouraged by him to pursue my passion to become a screenwriter and quit my day job and so we live off of his salary only.

As I started to learn, read, attend classes and write, I realized that this will be a long journey. It will take probably a good number of years till I be able to write well and make a living and be recognized for my work.

My dilemma is whether I should have a plan B or not.
An idea I keep thinking about is to acquire a fitness certification that is not a huge investment and one which I could use to teach classes in other studios rather than establish a whole business around, and one which could be a nice active supplement to my long hours of writing.
The dilemma is because there will be no negative consequences if I will pursue it or not, as long as I don’t need a day job.

It’s like there is a primitive part of me that says ‘You should have a backup plan’ and yet there’s a daring part of me that says ‘Screenwriting is my ONLY plan and I am totally going to make it no matter what. I do not need plan B. That’s the only option!’

What do you think?

With Gratitude.