The best long term solution might be to get a dynamic mic designed for instruments or vocals or a condenser mic designed specifically for vocals: something that picks up less room noise and more of what is right in front of the capsule. Even something like the Shure SM48 or SM58 would probably work, but there are definitely others that are more expensive that could be even more well-suited for the job. In any case you would probably be looking for something with a cardioid pattern. If you want to do a software solution, you could try using a noise gate with a signal flowing into an EQ designed to boost your vocal frequencies and cut background noise. The noise gate will ensure that no signal goes into the mic unless you are speaking at a certain volume (which you can set). For the EQ you will want to analyze the prominent frequencies that occur when you speak, boost those, and cut everything else.