I cofounded a startup that was eventually sold for $64 million. My cofounder forced me out of the company and stole all of my equity from me, costing me nearly $13M. So cofounders are not all they're cracked up to be.

As for the general negative tone, businesses fail - you don't, unless you quit trying. My advice: work on something with a short path to revenue for now, and stop taking yourself so seriously. After the thing with my cofounder, I had several ambitious ideas to make millions again, but those were failures and I was basically emotionally destroyed. So I finally made something with less potential, that was less interesting to me, but with a clear and simple value proposition for customers. I also developed a way to market directly to my potential customers for free. That business is now doing quite well, and the mere fact that people are paying for something I created has completely turned around the depression I was in.

Remember this: Walmart makes billions selling inexpensive crap that they buy from other people. Their innovation? They charge more for their products than they spent buying them. At least until you can afford to take risks on interesting, swing for the fences kind of stuff, get rich doing boring things. It's easier and faster.