I usually enjoy life and my work, which sometimes could be quite mundane, and then Covid struck and I was put on furlough for 3 months +
It gave me time to take stock of my life and realised I was very happy with my personal life but knew I had more to give in my employment side of life. Basically, long story cut short, I decided to look for something different so I applied for a number of jobs with my current employer but because I didn't have up to date certs I was getting nowhere so decided to look outside. I have recently landed a job as a maintenance engineer at a local college where I will be able to use my experience to a fuller potential doing a variety of tasks which, even though I have no formal qualifications for some of them, I know I am capable of.
It all comes down to having faith in your abilities and highlighting these when you are looking to diversify. You've been fixing boilers for 16 years so have skills that enable you to be continuously employable faith in your abilities. Ignore social media critics, we can all slag others off from the safety of an anonymous keyboard, most of the critics are actually inept in their own personal lives and this is the way they get the attention they crave.
Believe in yourself and have faith in your abilities. You will get knocked down but just get back up and carry on. The more you get back up the more confident you will become.