LOL, when I was halfway through your post, I was thinking, "I wonder if they've seen the Frank Grimes episode...."
As someone who's had a bit of Frank Grimes thoughts in the past, here are some ponderings that have helped me:
1. To me, the point of the Frank Grimes episode is actually positive and freeing--there will ALWAYS be unfairness in the world, and often it will be stark, raving unfairness--and the only sane thing to do is accept it, chuckle at its absurdity, and move on.
2. There are reasons you made decisions in the past, even if not evident to you. Let's say you could change things and go back and make different decisions. Let's also say those decisions meant that you were making $500K now, with a "perfect" spouse and children, leader in your field, "having it all", and I don't know whatever other "success" things. There is no guarantee you would be even remotely happy in that situation, and in fact, it could turn out disastrous for you. You made decisions for a reason, and they just might lead you to a life you would never imagine changing.
3. Most importantly: If you're going to compare, you should compare both ways. As much as you feel like Frank Grimes to other Homers, how many people would feel like Frank Grimes to you? There are probably literally MILLIONS of people in the world who have innate abilities, smarts, strength, determination, grit, social skills, etc., that if given the right conditions, would be insanely successful. But because of the conditions they were dealt, have to work essentially indentured servant jobs their whole lives. Or another example -- have you ever made a mistake in the past, and yet been able to recover? There are likely thousands of people, especially those not conforming to the "right" groups, who made a similar mistake and yet are NOT able to recover, because they are arrested/injured/punished/incarcerated/etc. such that they don't get the "do over" and are stuck with it their entire lives. These thoughts are not meant to provoke guilt or a "suck it up" vibe. It's merely an effort to be honest with what's going on, and thus freeing.
Good luck.