The water retention could be due to needing salt and/or potassium.
I gave up coffee altogether thinking I'd be better off. However, until recently, I had no idea coffee was so high in potassium. I started having water-retention problems when I gave up the coffee.
Guess who's back to enjoying her coffee? ;^)
(But, I do NOT count the coffee as part of my water, THAT is important, btw).