Even though you felt so burned out, and are still feeling it, I do think the time will come soon where you can look back objectively and see how much you learned. OK, your manuscript wasn't "the one", but the next one may well be.

Often it's the initial concept that isn't strong enough, not your writing. Just the fact you are now able to write about it fairly objectively shows you are moving on. I feel like I never stop learning with writing and all its challenges.

Good luck with the next novel!