Here's my advice, as someone fully employed who did the working like a dog thing for my own business for a while, and then for someone else for a while, got half burnt out and stopped.

1. Treat yourself as your own business. If your business is selling it's services for $50k a year, you deliver what you feel is $50k worth of services. Now that doesn't mean taking this to extremes (i.e. working 3 hour days). You fulfill your contract, but if you feel it's not worth your while to work 100 hour weeks, why bother? (100 hours is crazy btw, I do hope there's some exaggeration for effect involved there).

2. If you're slightly obsessive, find a side obsession. An organised one. For me it was sport, which meant training which meant having to be out of the office at certain times on particular days of the week. I didn't realise it then (I went back to sport after 4-5 years away from it through my college years), but that's saved my health, kept my interest in tech and stopped me from the burnout that was (for me, at least) inevitable. There is generally some social aspect to any hobby you can think of. Don't just practice the hobby, try and get involved in the social side of it. If you like chess, there's chess clubs / meetups. If it's photography, there's the same. Most people who are living the life that I've seen on this forum are at least mildly obsessive. If you're working 100 hour weeks, I'm guessing you're in that category. Find another thing to channel your obsessions into and meet people who share your obsession.

3. Find hobbies. This sounds weird coming after point 2, but I basically have my work life, my little side obsession with a sport that I train towards and I have my little side-hobbies that I enjoy and actively try to make time for. Again, move this out of your comfort zone. I went and took up surfing. I'm still a complete novice, and while at the start I absolutely hated the fact that I was crap at it I relish the feeling of not being an expert at it and having to learn stuff again all over. Most middle aged men where I'm from take up golf, this is something similar. They never become good at it, but it's relaxing, enjoyable and something to strive to get better at that's away from their personal and work lives.

4. Start living a healthy life. Seriously. You're obviously cash orientated and your outlook sounds very like where I was a few years ago. I'm a full time employee now, but I treat my employment like a mini-business.

Start eating properly, taking care of your body and getting exercise. Hey, I have chocolate cake, cookies & ice cream like everyone else, I just try to get a healthy breakfast, lunch & dinner most days.

These things sound like nothing to do with work... but guess what ... if you moved these things into your life, you simply cannot work 100 hour weeks. In fact, you cannot work 80 hours weeks, you'll be lucky to get away with 60 and you'll find after a while you won't want to even do that.

Ultimately I think I've found a slightly more fulfilling way to live life and still spend 40-50 hours a week enjoying my passion for tech. Also, don't mis-interpret me, I don't think I've found some spiritual plain. Some Zen heaven. There are days when I'm unhappy like other people, there are days when I'm happier, but I've found that ultimately, I feel like I have a balanced lifestyle and for me, keeping that balance has now become extremely important. People have noted how much my moods are better, I feel better & stronger, my mind feels more capable due to proper sleep regimes and reasonable eating.

my 2c