Do you find dehydration causes flare ups?

I've had an ongoing flare up for about a month now. It'll clear up for a few days, but then if I have one bad day where I drink a bit less than I should - boom, it's back.

I've also been ill with a cold for the last week or so, which has now progressed into tonsillitis (yay for me), so I've been really struggling to drink enough water because swallowing is so painful. As if the tonsillitis isn't bad enough, I now have that constant burning sensation too.

It seems to come and go very quickly lately, the burning will last a few hours, I'll chug a couple of litres of water, pee, and it'll pass again. But then it comes back any time I slip up and forget to drink.