Go and get checked for sleep apnea.
This was happening to me alot. Waking up multiple times a night, desperate for water, like, pints of it, then do a big wee and back to bed.
I started getting issue with staying alert and awake in the day, i was dozing off in work meetings (not fully, but like when your head dips and just jolt awake again)
If you dont have it, then great, mark that off the list.
If you do have it, get it dealt with because it's bad for your heart as your body uses adrenaline to wake you when you stop breathing and leaving it untreated shaves years off your life.
If you let it go too far you can be suspended from driving and all sorts until you get it under control.