There are home kits for putting on false nails. I am a little nervous about the solvent you need to remove them.

You can try "Alaska picks". They are designed to be used "rightside up". That is they go over the nail and you pick with them as you would with a nail. They don't feel exactly the same as a nail though. There are sizes meant to be put on the thumb and they should fit chubby fingers. They come in metal and plastic. The advantage of the metal ones is that you can bend them to fit your finger just right. The advantage of the plastic ones is that you can trim and smooth them like you do nails.

Personally, I use finger flesh when my nails break. Even on a classical guitar. I don't have the patience to adjust to picks of any kind.

Murray