I think you're being way too hard on yourself. There's no shame in moving on if you think it's time and I agree that Toasty is a great guy to pass the torch to, but I don't consider you a failure by any means. I know it may feel that way some days. I have days where I second-guess everything. Our minds can play tricks on us and we can often be our own worst critics. But you gave it your best shot and you had good intentions. You deserve to give yourself credit for that. Part of being a GM is taking risks and, unfortunately, risks are often judged only by the results. Someone of the trades I've made have been blasted; others have been praised. But there's a lot of luck that comes with that and unfortunately that's a big part of the way our decisions are viewed in hindsight.
At the end of the day, it just comes down to what will make you happy and, if being a GM isn't making you happy, then it's time to pass that role to the next person. Just focus on your personal happiness, try to be the best friend/teammate you can be, and only worry about the things that are in your control.
At the end of the day, it just comes down to what will make you happy and, if being a GM isn't making you happy, then it's time to pass that role to the next person. Just focus on your personal happiness, try to be the best friend/teammate you can be, and only worry about the things that are in your control.