Sweet! Sorry you got a piece of glass in your foot! and I hope you can get it out!
I have a short rolling stool, that is used for auto mechanics, etc. It is great, and adjusts down to very low. I sit on it when I bathe my doggy in the tub...otherwise my back would be in great pain. Also good for weeding around the sidewalk, or just working low. Not expensive. You can get one from Harbor Freight Tools for around $20.
Patty