I was getting tired of seeing my last, depressing post up at the top, so I wanted to add a quick, more positive note to what I most recently wrote.
Look, this process is really difficult. It's mentally exhausting, and it's easy to sink into self-doubt surrounding how long you've been in graduate school (or academia in general), or based on the job/house/family/etc you gave up to pursue your academic dream.
But, look. You are not the first person to ever make a career change, or to have life throw you an unexpected curveball that sets you back a few years or a few dollars. (Nor am I - haha. :)
Think about people across history who spent years as prisoners in war camps. Think about people who fall seriously (but temporarily) ill or have a catastrophic injury, for which they have to quit working for a few months or years. Think of people you know who floundered a bit in their teenage or undergrad years and took a long time to get started with their career. Think of people who are victims of natural disasters, or who lose their jobs unexpectedly.
Most of those people will be just fine in the end, and ultimately have fulfilling work and family lives despite a few years' of setbacks.
The truth is that life is full of lots of hiccups and lots of unexpected pauses, slips, and time-outs. But most people recover from those periods just fine. Plenty of people returned from war camps to have successful careers and families. Plenty of people who floundered or even got into trouble in their late teens and early twenties find their way to decent careers and fulfilling family lives later on. Plenty of people who miss a couple of years of productivity due to illness recover and resume their lives. And this week, looking at the devastation in Joplin, MO? As bad as things are for them, those citizens will get back on their feet, rebuild, and move on ... even though it will undoubtedly take some time.
People have faced bigger setbacks and have come back from them. You (and I) will get through this decision to leave academia for something else, just fine. A few years' lost productivity is a million times better than a lifetime in a career that you hate. Even if it takes a little bit of time, you are going to be just fine. You are (most likely) not being forced into this situation - you are choosing it. And if people can recover from unexpected cateastrophes that are thrown at them (and have done so countless times throughout history), you can recover from a career move that might set you back a few years, but that you're fully in charge of.
And in the end, you will be happier.