I am in a similar situation, but for a different reason. Looking after children is not a subject anymore (17, 19, and 21 in the meantime), so I started my first steps into sailing a few years ago with my wife. In the meantime, she is more into yacht-sailing. I recruited new crew, and with two of them I am able to participate in races, but I bought a pretty old A-cat for the rare occasions I find nobody to sail with. Right now, I sometimes join my wife and her buddies on the yacht, and she joins me from time to time. So, my advice is: keep the F18 and buy an A-Cat. You're in Europe: the time to buy such a boat is better than ever. Due to the conversion to curved dagger boards, the prices for 5-8 year old boats (Flyers) are dropping dramatically. At least here in Germany ...
Kai