2 mental break downs in 5 months, I don't think I can make it to Q1 of next year. The Principal engineer who left shortly after I joined, said the same thing about 'hoping things would get better'. He was always waiting for it to get less shitty, but that never happened. It feels like a bait and switch, but with a twist of insanity haha
Your mental health is far more important than some empty promise that "things will get better".
Hint: they're not going to get better, because the problems you have are orthogonal to how the business operates. As long as they can remain profitable, they'll wring every last drop of productivity they can from you and replace you as needed.
They might not state it as such, they might not even know they're doing it--but the fact that "things will get better" date is a fiscal year should hint where their priorities lie.
Get out--you don't owe them anything.
But there's more to it than that.
De-brief yourself. What did you learn? One thing you may come up with: your health is more important than any job. Another suggestion: it seems that you may have taken on more than anyone expected you to take on, including yourself. You might want to ask your boss' opinion on this. They may be surprised at how much you've been doing. Perhaps not.
Take a break. Just phone in sick: you are sick. Being sick doesn't mean you have to stay in bed eating pills. Get outside, go for a walk, blow the cobwebs away, get some exercise perhaps, just step away from computers and the internet. For the first day don't even think about work. Then on day 2 try imagining what you'd say to someone else who's in your situation. Things might become clear.
Good luck!
Get out. You don't "hope" things change, you make a plan, then you execute the plan, and you make corrections as needed. You don't hope. Nothing happens when you hope. Unless this quote is vastly out of context, I'd say there's no hope.