Thanks for your advice.
I cannot see a complete career change working. Despite my misgivings, I'm paid well and have a heavy mortgage I could not manage if I were to become junior in a different field.
"Escaping the environment" in the form of moving to another city or country is certainly an option I need to consider.
I completely agree with your points. I run two side projects (non-monetised) which keep me very entertained. I've attended security conventions (for which I take annual leave, and receive strict instructions never to let a client know) and overall I have a very optimistic attitude to what the industry is capable of.
"Escaping the environment" in the form of moving to another city or country is certainly an option I need to consider.