It's great your trying to improve yourself, but that also adds stress when you can't manage expectations well (which isn't easy anyways for many people).

You can leave and take a break. Or talk to your boss. I don't know what your responsibilities are but it's never worth it to go burnt out for a long time. You risk breaking yourself.

I experienced that and it sucks, big time. I'm becoming stronger because of it. However, I'd rather see people learn without going through that.

I suspect you're worried about the consequences of talking to your boss. If he's an asshole chances are that was already contributing to burnout. You'll win if you get canned. It doesn't reflect on your skills so don't let your ego get bruised because of a trifling matter. If your boss is semi-human, you also win.

What helped me a lot was therapy and yoga/meditation. In yoga, good instructors reinforce forgetting about worries of life for a "mere" hour and focusing on myself. Once I stopped resisting that concept, life started improving rapidly. It's a hard thing to go, dropping "everything". Finding someone to talk or a group of people who understand is really important and there are many people who have gone through these kind of things.

Many don't learn or understand the meaning of priorities until the experience something traumatic.

So talk to your boss and don't quit before finding a new job. Or quit and take a long break.