I'm mid-fifties: I'm on career 4 right now. Each of them I was fully committed to, rose to a reasonable level to, made good money at. Each disappeared, and I had to re-calibrate. I was an engineering design model builder: combining a watchmaker's accuracy with an engineer's understanding of process flows in factories and plants and ship engine rooms. Early computers wiped this out.
Then i worked as an exhibit builder: World's Fairs, Science Centres, industrial exhibits: that got wiped out by standardized aluminum extrusion booths, lowered budgets - it's not that it's gone, It's just so much smaller, and much of it is now done with video screens.
Then I became a multimedia developer, creating CD ROMs for government agencies, banks, schools, and so on. The web wiped that out when I was about 7 years into it.
Finally, I became a web application developer, and that's still around. But you know, they won't hire old guys like me. And maybe they're right, or maybe they're not. I put a decade in, I was a founder of a startup, I sold some code, I was a lead dev.
In between, I taught technology in schools, colleges and to individuals. I worked as an illustrator on the side. I helped a few world-famous artists create sculptures and other artworks that were in major international art fairs and major collections. I shot a few experimental films. I raced and built bikes. I renovated houses and made money that way, my own and others. I designed and built kitchens that I'm still very proud of. I had a company providing zinc bar tops to restaurants and bars.
So, I'm sorry that writing isn't working out for you. But even though I have less security than I maybe hoped for, I've lived a life. I'm on to my next career: building a school for people who want to bootcamp their way to a new career: it's focused on people who are entrepreneurial, ready to challenge themselves, who don't believe that what they have done is all they can do. Check it out if you want: http://www.rubyonthebeach.com. I'm plugging it because it reinforces the point I'm making here, not because I spend my time spamming comments. I don't.
Main thing is, it would be great if life was different, but it isn't. Move on.