+1000 Second job.
Start small, maybe put it out there to be a friend handyman for all your mates. Do it for free or nearly so. It would be a good way to build your skills and also get your name out there a little bit. First it would be friends for free, then acquaintances etc. At that point you could turn it into a real business if you really wanted.
I kind of have the same experience as you, a bachelors and masters degree, fancy shiny expensive degrees just to find out I really want to be a construction worker! Not for someone else though, which is what I wanted to bring up. Doing electrical 40 hours a week for a company where I am just another employee would suck all the fun out of it, so defiantly think about starting your own firm.
That being said, I would want to plug real estate here, you are in the UK. I cant speak to anything over there, but I can speak to experiences. Having a rental house you have to work on from time to time is a great way to learn. Plus it does not have to be 'perfect' just functional in the things you are working on. Also this is a low risk way to get your feet week and have high certainty of some return (rent).
The last thing is say you have a handyman business or rental company on the side going. Its a nice little income say maybe 1/4 of what you make now with 1/8 the work. Having this makes your day job so much more bearable. Because you know in the back of your mind you could walk out of there and be just fine. You no longer have the fear of getting laid off, not doing a good enough job etc. On some level you would not mind getting laid off at all! Building a business is some of the best work you can do IMO.
YMMV good luck and keep us posted!