Do you have a family to support? That's a big factor in how much risk I can really take. If I was single, I don't think I would have any issues taking a break to work on this project.
I actually have a pretty good nest egg established from another project I launched about 10 years ago, but I don't think it's enough to responsibly depend on exclusively to support my family while I work on this.
When I first brought up my career change, she wasn't on board because I didn't have a plan. But now that I am (more) sure of myself and know what I want to do and how, she is happy to support me and I'm exceedingly grateful for that. As long as you're communicating and your family is supporting you, I'd bet you can find a way to make it work.
I was reading about director Ang Lee a few months ago and found some inspiration in his career. After finishing grad school, he spent the next six years unemployed, writing a couple scripts at home and taking care of his two small children while his wife (a molecular biologist) worked. If he had given up then or if his family hadn't believed in him and supported him, he probably wouldn't be where he is now. Everyone's situation is different but I found hope and comfort in his backstory.
I'm very risk-averse but finally worked up the courage to quit and spend my time doing what I love: writing music. I'm slowly bleeding through my savings, but it's worth it. I wouldn't be able to live with myself if I never gave composing a fair shot. In the end, the biggest risk is actually to your ego. There's always another job out there, particularly if you're a software person.
I'm still nervous about the whole thing and worried about my prospects. I still procrastinate. But damn, I'm just much happier these days!
Finally made an account after years of lurking just to say this. Believe in yourself and take a leap. Sometimes it's just what you need to rediscover yourself.