What I really don't want to happen is getting into a 'career' which turns me into a depressed robot who moans about their life all the time, and never gets anywhere, and has no energy for the hobbies they used to have before they sold out.
Does anyone know where I'm coming from?
I know exactly
where you're coming from. I left behind a career as a "professional geek" (networks, system administration, tech support) a few years ago, mostly for those reasons. I loved my job, but the hours and the stress took up entirely too much of my life.
Now I'm a massage therapist, which is possibly the most stress-free job in the history of the universe. I'm self-employed, so I don't work long hours unless I choose to. At the end of the day, I feel like I've accomplished something positive, and I still have time and energy for the rest of my life.
There are plenty of jobs out there that don't fit that stifling "career" mold - just keep your ears and eyes open and you'll find it.