I was in a similar situation for a month recently. I now have a bench, but I did nothing but floor presses for almost four weeks. While at first I hated it, it actually made a huge difference for me. My starting point strength went up and, as an added bonus, floor presses require you to use your arms a lot which, after several weeks, added noticeable muscle to my arms (particularly triceps).
Look at it as a positive thing and make the best of what you have.