I constantly feel thirsty.

[MrRazot]

Ok, I think I've found the problem.

Back home in Orkney, temperature was averaging at around 6 degrees Celsius, and now that I'm back to boarding at school in Somerset, it started averaging at 10 degrees. I think that my body hasn't adjusted to the temperature changes well. I hope that that was just the problem. If it persists when I get back home in July, I'll look into it further. Thanks for all the help, everyone.

Something I thought of today. Water quality can have a lot to do with it, and if the water you drink is overly processed, then it can actually dry out your mouth. I had that problem when I was in boarding school. The water from the taps was like drinking swimmingpool water. But yeah, try drinking more bottled water or even get yourself a water filter.