I have plantar fasciitis so maybe I can relate.
Exercises that don't hurt my foot are body weight stuff like: squats, dips, pullups (assisted or Australian), overhead press. All these things are pretty easy to do on your own without a gym. Overhead press is nice because you don't necessarily have to be on your feet to do it. Remember, you can lift anything you like over your head or squat with stuff too. Maybe try a gallon of water or something like that.