I'd think they could genetically engineer the egg layers to only produce males in certain conditions (such as when they're incubated at a higher temperature), then only breed males when they need more roosters.
OR, if sex is selected by sperm type (as with humans) artificially inseminate the hens.
I suspect there are dozens of valid technical solutions that are cost effective and would allow them to not shred male chicks.
Every vegan initially dreams of a world with ethical meat. Then after a few years you realize you actually don't miss meat at all. Please believe me when I say, ethical meat really isn't worth the effort (and often mental gymnastics).
For now, to paraphrase Marge Simpson, I can’t afford to choose a diet that has a philosophy I'm sure that yes, unprocessed vegetable matter is cheap if I know where to go, but turning that into a run of meals that doesn't trigger my major depression and suicidality is simply not feasible. Also there's the concern that when I endeavor to do complicated things and fuck up, the cost of the disaster is exponentially greater than the cost of not doing it in the first place.
In short, getting ten pounds of legumes would be a great way for me to ruin ten pounds of legumes and stink up the street block.
I've heard that people who actually know how to cook are able to do wonderful things with vegetable matter. But I do not have access to them, and their pre-processed products at the store are more expensive than meat and eggs.
Sometimes I fantasize about a society in which one's status as a person wasn't contingent on how much money I make for someone else, who is glad to give me a tiny portion of that take, but we are a few generations, and a couple of great filters away from such a pipe dream.
I'm lucky in that I'm very content to pour a can of beans on rice and call it a meal. But I can sympathize with your situation. I'm very sorry to hear about your mental health. If I may offer a suggestion, if you can't be 100% vegan, then just be as vegan as you can be. Choose the shirt made from cotton and not wool. Experiment with vegan food a little bit at a time and learn what you like. Buy the fake meat when it goes on sale. Maybe it'll work out, maybe it won't. But if you take it slow and gently then you probably don't have anything to lose.