What in Las Vegas is making my whole family sick?

Well my first thought was: gambling! Gambling is sick and makes people sick. But your description makes this theory implausible. Have you spoken to your new neighbors about this? If no other neighbors are experiencing the same symptoms, then there may be a slow natural gas leak in your home. Or tainted tap water. Or fumes from a nearby factory blowing directly at your residence. Bottom line: you obviously need to contact a family doctor, or a local environmental organization, or both. You need to let some experts know what's been going on in your household immediately!! Don't just sit there scratching your heads. Use them! Get out of the line of fire, Mammy! It's most likely your environment is sick, not you!