So I was in a similar position, starting in trades and moved to an office job because I was afraid if I kept at the trade I'd end up disabled by middle age (I'd already sustained serious injuries as a kid that were being made worse):

Firstly, I want to commmend you for recognising work is causing you problems and seeking help to remedy this. A lot of men just bottle this up and take it out on their partners/kids

As you say though you can't really afford to take risks due to the commitments you have so your options have been narrowed by taking this on at such a young age. I also think you're probably a bit restless just being a lad in his early 20s in general - if you didn't have kids I'd tell you to take a year off to go live it up and travel

I would, personally, recommend sticking at being a sparky. The risks of career change are big with kids and, frankly, the grass is rarely greener. (Office jobs for example are far more alienating, and although less physiclaly demanding leave you feeling even more mentally exhausted)

Whoever you work for is clearly taking the piss with those kind of hours, so to start I'd be keeping an eye out for similar level jobs elsewhere and get applying.

I know it's not what you want to hear but if you think you're tired now it will only get much, much harder in your 30s so try to use this time now to get ahead - build up your skills, experience and (most importantly) CONTACTS

The ideal situation for you is to work for yourself in your 30s onwards, or to be managing bigger jobs, where you have control over the hours you work and are getting paid more than enough for it.

You can achieve this by building that experience and knowledge until you're confident enough to not only take on jobs yourself but to build up a network of potential clients. Every home renovation that requires electric work needs a spark and if you can make yourself the port of call for a number of middle class homeowners you'll always have a pipeline of work and you'll be able to pick and choose (they'd much rather wait for someone they know and trust to do a job)

This is the path many of my friends from school took: start as a tree surgeon/plumber for someone else, learn the trade and then once you've got familiar enough with a number of clients move to work for themselves and take the clients with them. They had to graft hard in their 20s but now they're very comfortable in their late 30s - and you will appreciete this breathing space more as you get older!

Lastly, you may feel you're missing out by having kids and a mortgage now (and possibly seeing your mates without responsibility having fun) but think of all of this as money in the bank. You can make the rest of your life so much easier by giving up a little now and your kids will also appreciete this more once they're teenagers wanting to scrounge money off you!

Good luck to you