I've suffered from something very similar, other people have advised getting some exercise and you should definitely do that, I've found it helps. You mention

I've suffered from something very similar, other people have advised getting some exercise and you should definitely do that, I've found it helps. You mention that you don't sleep very much and tried to sleep more for a few nights, try to continue that for a couple of weeks and see how you feel. Something that often isn't mentioned with respect to sleep is consistency, go to bed at the same time and get up at the same time, every day - even on weekends. I personally struggle a lot with this one, but it has helped me a lot when I adhere to it. Even when I don't manage to go to bed at the same time on the weekend, I make sure I'm at most an hour late. Good luck!