I am coparenting with my exH, so I have the children for one week and then they are at their dad for the other week.
My 'single life' week I cram full of socials and my hobbies (I have quite a few :-). Then on the week where I have the kids it is all about clubs, school pick ups, birthday parties, cooking meals, walking the flippin dog (kid 3, effectively), sports day etc.
Every week I find it SO hard to switch gears. I know this is totally first world problems, and it sounds really bad, but I go from living my best life doing whatever the hell I want one week to being a fulltime parent with everything (and rightly so) revolving around the children and being restricted in what I can do and who I can see.
I just need someone to go 'yeah me too' or 'yeah me too but it gets easier', I don't think there is a solution to this really other than just trying to make the kid weeks as fun as possible!