The thirst, you might drink and drink with little to no urine output at first and then the urine output catches up a day or two later.
Accept any and all help that is offered is my advice, putting the bins out, cutting the grass, errands, collecting your children, and meals if offered.
Suggest getting an A4 notebook - just make a list, write down things as they come to mind. The list will look and seem overwhelming - but so long as it”s written down, you can deal with things in differing timescales, and take some of the weight out of your mind.
If friends ask what they can do to help - please do pick things from the list that you can delegate.
Maybe just achieve one or two things a day - and that’s enough.
Maybe in the morning, or whenever your best time is, then stop and just rest in the afternoon for example.
I wouldn’t be in a hurry to tell organisations - it can wait. For example maybe don’t rush to tell your bank - let it just continue running itself for now if you can (my bank were shocking and just added to my problems)
Try and regulate your breathing with some deeper breaths sometimes, as best you can.
As others say, just concentrate on getting through the next 10 minutes, the next hour. Try not to think beyond that just now.
So very sorry for your loss.