This is a great case study, and congrats on your result!
Take heart, now that you've built up your ability am pretty sure you can run 16s with less mileage throughout the year and a shorter buildup than what you did, allowing you to focus on other aspects of training during base phase or off season (strength, power, endurance).
- Am concerned about your all out 200s, longer term this sounds like potential for injury and staleness. Kipchoge says he never runs harder than 80% in training, though marathon is a different beast
- your 10k/half times are relatively slow, maybe focus on them for part of the year
- recommend training in a group at least 1 or 2 days a week, e.g. long run or workout, might keep your mind fresh and give you other training ideas
- i like your polarized training approach of easy-easy days and much harder days
- reading this: "Depression and anger comes from investing a lot of time, effort, sacrifice, etc, and failing and having a bad race...." sounds like you're a perfectionist? A coach or running partner(s) can help. Get curious about failure rather than depressed. It's motivating to strive for a lofty goal, but dealing with "failure" is as important.