I have a strong gas smell inside and outside when I turn on my heat

That doesn't make a whole lot of sense to me since those two systems don't really cross paths. You could be sucking up fumes from under the hood and blowing them through the car. That would indicate a fuel leak under the hood. Take and get it inspected immediately. http://repairpal.com/chevrolet-within-10-miles-of-west-point-mississippi-39773