I find that relaxation doesn't help at all. Even after taking about a half year break after selling my startup, I was still burnt out. What helped me out of it was teaching.

Quoting Tony Robbins: "The reason you're suffering is you're focused on yourself."

It's a powerful enough quote that I'll probably print it and put it in my office.

Don't think about the work. Don't think about the pay, the holidays, the things you will buy, the fame you'll get.

Instead of focusing on the work, think what you do with it. Think of making them very happy. It could be a client or customer. It could be your boss.

Instead of focusing on the money, think of what you can do to make people happy. It could be bringing your significant other on a vacation somewhere. It could be buying your daughter a new toy or bringing them to the zoo.

You can also try giving back - if you're a techie, you can teach people to code. Or answer questions on Stack Overflow. Write articles and blogs. Make videos on Udemy. Don't focus on making money from it but on passing down your experience.