The smell coming from my fish tank is making me sick.?

uhhhh try those water packet things you are supposed to put in your water that you can get at the store. I clean my tank (guppies and 2 tropical fish) every 2 or 3 months and mine is fine till then. ( no one even say I shouldn't have 2 guppies and 2 tropical fish together, because they have been happily together for two months now, and the tropical fish have been together for a year now.)