You definitely need to have someone come in and refinish your floors. I understand if you have to use a "band aid" in the meantime until you save up enough for a pro to come in and take care of this bear of a job. I wouldn't waste too much effort sanding etc. though. What I used to always do when I was young, poor and renting, was to buy a tin of "Liquid Gold". This stuff is some sort of furniture oil that you should be able to find somewhere. Just slather this stuff on with an old rag and your wood floors will look pretty darned good. Be advised that they will be slippery for a few days. You might not want to use it on, or near wood tread stairs unless you have runners. In most cases, your floors will look near new and you might not even get them sanded after all.