Re: Is it possible to "make my own mat"?
I remember a discussion on this topic, somewhere (perhaps in real life, rather than online). I think you can put together a mat with a bottom layer made of pulverized rubber tires, and a top layer of thin foam, or that stuff they put under carpets. Actually, several layers of the carpet liner, on its own, with a canvas cover, might work. I heard that the pulverized rubber tends to move around a bit too much over time. The basic idea is to have something squishy (but not too squishy) with a frame and a cover. I know there's an article on this out there somewhere.
You might look into getting used wrestling mats from a local gym or school, and using those temporarily.