Keep trying. I recently turned 59, kept looking at job ads for developers thinking "I could do that, but...I'm too old, they won't want me, who am I kidding", etc.
Two days ago I was wasting time at the computer (funny cat vids) and drinking some wine. I checked my gmail and decided (who knows why) to check the spam folder. Right at the top of the list was a email from Airtasker (the odd job site), which I joined about a year ago and promptly forgot. It had come in that day and was from a guy who ran a small digital marketing agency. They make small business sites with Wordpress and Bootstrap.
Business was growing, so he was looking for someone with Wordpress, Bootstrap and PHP knowledge to help him with the coding work. His daughter handles social marketing, etc. The task was to meet him and have a chat; see how we got on.
"I could do that", I thought, and normally that's where it would have ended. But that last wine, and the fact that his profile pick showed some grey hair, did the trick. "#$&! it", I thought, and sent him an offer. I told my wife what I'd done, and went to bed.
Next morning I checked my emails, then turned to my wife and said, "Something terrible has happened. He's accepted my offer and wants to meet tonight!" I was seriously worried. All the old doubts were banging away at me: "He'll take one look at you and laugh you out the door.."
To cut a long story short: we met for coffee, got on like a house on fire, stayed chatting for an hour - and I'm in!
Ten hours a week for now, so I ain't giving up my day job (I'm paying the bills working as a courier at the moment), but in the meantime I'll be getting real world experience and building a portfolio. We'll see what the future brings.
It's not a cool working-with-the-latest-frameworks job. But it's a job. A web dev job. And it's mine.
So keep going, and keep applying. Beat that inner critic down!!