You might want to try this: near the end of each day, think of 3 things you did well and one thing you're grateful for. Things you did well: not perfectly, but well. E.g. if you make a salad with pieces that are a little too big or too small to put into the mouth easily, or you forget to include one vegetable in the salad, it still tastes good and is healthy and can be something you did well, especially if you enjoyed it or were glad you had done it or did it better than another day. You can just think of things or say them aloud; you don't necessarily have to write them down or save them in a list. It's to help you feel good about stuff.
Inability is an abstract thing involving comparison with alternate universes; it cannot be experienced.