I tried dairy-free, gluten-free temporarily. It turned out I didn't need to, but in the end I rather enjoyed the fact that I was forced to try all kinds of new foods, some of which I still eat.

Yeah, no ice cream. There are still plenty of wonderful yummy foods out there. Popsicles. Sorbets. I made a pumpkin pie, and I still use that  crust recipe. One of the finest, quickest, most child- and adult- friendly deserts you can make is a tofu-based chocolate pudding. You'd never know it's tofu. You can get Mori-Nu tofu and add their chocolate mix (mainly cocoa powder and sugar), or Alton Brown has a scratch recipe for it. I make it all the time. Open tofu, add to blender. Put in mix. Put in water. Press button to blend.

The hardest thing is breads, but there are many options; it's just a matter of finding one that appeals.

There are so many internet resources out there that I think you'll find it less difficult than you expect if you are already accustomed to cooking. (It would be much harder if you usually eat in restaurants.)