I would say, try to work on something that you might actually find fun, for myself when I am tired of boring projects I make little games. It's something I real

I would say, try to work on something that you might actually find fun, for myself when I am tired of boring projects I make little games. It's something I really like and keeps the mind active. But sometimes it's also good to take a total pause. If you really feels that you can't work on anything try to stop thinking about it, look at other things to do, some other stimulating projects like a DIY. One last thing could be, don't stay alone, find a co-working place, or a bar, or something where you can stay in touch with people, this is often underestimated but important.