I started sewing about 4 years ago, 35 years since I last made some curtains and a few bits and pieces of clothing for my (then young) DDs. I can sort of feel what you are experiencing, as I have made lots of T shirts, shorts, leggings, pyjamas, shirts and dresses for my GC, but they are coming to the age when home made is just not for them. Maybe not the youngest, 7 year old GS, but certainly the older GD. Luckily I now have a 5 month old GD and my DD2 loves anything I make for her!
However, I have certainly slowed down on the making front. Perhaps I could have a look at things other than clothes for their school fairs. Is there a local primary school that might appreciate your work? Or the idea of a local group sounds promising - sociable as well as useful!
I envy your crochet, cardmaking and patchwork skills, wish I could do those! I used to make cards for family birthdays and Christmas but only using a computer programme, so I couldn't claim any artistic merit!