What do you do in your spare time - read, watch movies, follow sports...? If so, what are your preferences? Also, while I don't suggest wallowing in your feelings of depression, it is worth learning to listen to your depressed mental monologue for clues about whatever-it-is that you are not doing because you're stuck on an IT treadmill, 'eg 'to think that I used to dream of being an Olymic figureskater but I ended up writing middleware....grar...'. Most likely you still have dreams, but being mired in depression means everything is covered in a sludge of negativity and you 'know' that none of them are achievable now so that you have trained yourself not to let your imagination run free.
Good advice about trying to let go of the things that are holding me back. I've thought more about going back to school, but not sure what I'd want to study.
But it would give you something nice to do outside of work, and you can leverage technology as much or as little as you prefer. This would at least 'stop the rot' by compensating yourself for The Job You Hate in the short term, and might help you open up mentally to other possibilities int he longer term. If you're naturally talented you certainly have an edge over me.
It is hard to give very specific advice without knowing more about your particular situation.
The only thing that I can advise (and that helped me a bit) is to make a change, ANY change. Even picking something addictive like http://na.leagueoflegends.com and playing it helps if you make a __realistic__ goal (I'll get to XX elo) and then follow up to getting to that point. Satisfaction mostly comes from making the goals you set and probably your biggest problem was that you had no motivation even to set the goals (that's why I suggested something addictive in which it'll be easy to get motivation for goal setting).
I turned to sales engineering. A few years ago I noticed that I'd gotten better at socializing and social interaction, and, more importantly, at the end of a day where I spent a lot of time with people, rather than my computer, I felt more energetic.
As a sales engineer you can make a similar salary and leverage all of your skills and your abilities. What do you think?
In order not to fire him immediately, the CTO elected me take him to a psychologist. Guy invites me into the session, the sum of which was "go home on time, leave the computer off, and every night, walk until your feet hurt."
Within one week, he was well-rested, smiling and happy. I won't say back to his normal self, because he was a pretty weird dude!
When I felt I was burning out, I tossed my computers, reduced my belongings to a bag, and moved out to a farm to learn goat-herding. It was a deep, soul-recharging experience. I found that in my old city life, I was weak, dumb and blind. I couldn't think and I couldn't hear. When I left there, I felt like Moses, with all kinds of deep insights and shit. And I was healthy as an ox.
Unfortunately, not everyone will make such a radical change. They will have a bunch of excuses, or are looking for a more convenient solution. You know, the same kind of fear, feelings of obligation, and other flawed thinking which gets us into these things in the first place.
My friend, you need good food, sleep, time where you turn everything off, and plenty of exercise. Everything else is just a band-aid.
If the shit hits the fan, all you have is your family and your health, so you get yourself healthy. Scrub toilets and be grateful for it, if that is what you need to do. Level your pride and repair. Opportunity will be waiting for you when you are feeling better and ready for it.
But... understanding myself didn't help with avoiding the trap I fell into that caused all this - I got screwed over by a 100% sociopath, and even though right now I can "see" how my blind spots were preventing me from properly dealing the situation, I still am going to go to a therapist to work out not the "understanding" of what went on, but to deal with the emotional impact of it all - it is much easier to do so with the help of someone and not by yourself
I'm certainly not recommending years of therapy - tell the therapist you're interviewing you see no need for sessions about your mommy and daddy (if you don't think that was a factor). You have a general goal - to get over the burnout, understand how you fell into it, and to figure out the next direction you want to go in (right?). Then a good therapist would draw boundaries around that - e.g. 10 sessions, then check to see how complete the goal is. Thus you need not get drawn into years of psychoanalytical blah blah. IF the therapist pushes you to do otherwise, then they are not the right one for you.
I too am conflicted on what I want to do next, and I need to understand my ambivalence - then hopefully I will get the confidence or energy needed to tackle the problem. But there is no need for extensive navel gazing at this time.
Anecdotally, I consider myself lucky to have been convinced to see a psychiatrist (after considering it frequently over the previous decade). After a few months on medication, a few talks with some friends and colleagues about what was going on (and discovering that some of them have had similar experiences), I started to get a degree of perspective I hadn't felt before about my relationship to work. Not terribly much longer I started doing side projects for fun, after years of declining interest in pretty much everything I used to enjoy.
Finding a job you enjoy can be hard and take some time, even if not considering a career change. I would caution against wholesale avoiding using your existing skills - they may be useful as a way into a new job that will afford you an opportunity to try get closer to something you are interested in trying out. Also, trying a totally different type of organisation, if available, is also something to try, even if using the same set of skills, since often people enjoy doing things more with the right people, or with the right mission or feeling of doing good in the world. (So, maybe a charity/non-profit, or a family concern instead of a "company".)
Try not to be too afraid of taking incrementally-closer-to-what-you-want jobs as you find them (ie, always be looking and talking to companies), even if it means only spending a few months at one or two companies on the way (assuming your previous career shows a stability future employers might want to find).
(I'm happy to speak to you offline if you like - my contact details are in my profile.)
(It's not a solution to all your problems, it's just an experiment to see how it affects your consciousness.)
Yes, it's very difficult to switch from software engineering to sales/marketing field. But I learnt a lot more about software engineering when I worked as Sales guy.
Currently I work as Software Developer cum Sales Engineer.