Dehydrated feeling

34 weeks tomorrow and I constantly feel like I've been in a desert without water for weeks no matter how much I drink and everything flows straight through me I'll drink a glass of water then pee not even 2 minutes later. I just peed twice in a 5 minute span of time and both times were like full bladder pee's not a tinkle here and a tinkle there. Why am I SO deHYdRAtEd?! This can't be normal😵😩😰 Send help.