Burnout is inevitable. Fixed working hours have become the biggest sticking point for me in the home office. What has helped: having your own office space that you enter in the morning and leave again in the evening. Fixed working hours so that you can really regenerate afterwards. This is incredibly important, especially in creative professions, so that you don't burn out completely. And the office can stay locked at the weekend. At least on Sundays.
2. Maintain your own appearance Sure, this may sound like I'm some shabby guy from turkey whatsapp the gutter, but the fact is that I don't shave every day if I know in advance that I'm just going to be sitting in the office that day and don't even have to go to the supermarket. But that doesn't mean that you become neglected yourself, but rather that you let the little things slide. Why shave and why wear a suit when sweatpants are much more comfortable and so on and so forth.
Make sure you don't neglect routines like this. No working in your pajamas or sweatpants, no neglecting any of the things. Make sure you always get ready like you would for the office. I found it difficult at first. But I have to take the dog out four times a day anyway and since I meet a lot of people I know there, I have to look presentable. That really helps me not to let myself go.