Totally lost after being self employed for over 22 years. Anybody else been though this?

After university I struggled to find work so I wrote some code which turned into a successful UK business of over 22 years. I never imagined it would pay my bills this long but it's waning and I just cant compete anymore.

I feel like a jack of all trades, admin, tech support, software development.. I'm absolutely lost and don't know where to start in the job market. INCREDIBLY daunting... Has anyone else been though this and have any tips as to where to go and how to get started? Maybe at 45 it's time for a new career whatever that may be?! I've hardly had a day off in 22 years... laptop always come on holiday with me.