Here's an approach: Put a number and a deadline on everything; this way you have a metric to hit rather than dealing with emotions.

So for example: Can you at least equal your current monthly income in X months? Make that a comfortable number so you don't run out of savings and have enough time to get a new job.

I would also have a metric on the burn rate of the company even if the overhead is low. Keep in mind you'll need to also be spending money on marketing, and the services of an accountant and the like. You don't need a 100 page business plan, but you do need a plan.

Also make sure that your spouse feels good about this, because being in a good emotional state is critical for the both of you.