I had a plumber out because I have a sewer gas smell in the home he first replaced a small cap / vent under my sink that is supposed to keep gas from coming inside. That did not work then we found a leak from the kitchen sink that was dumping water under my home on the dirt ( I have a crawl space )after repairing the leak he told me it should go away. I opened the crawl space vents and set a fan at the crawl space opening to let the gas out. It is now getting below freezing at night and we are unable to keep our windows open and I have closed the crawl space door so the pipes won't freeze but my house and under my home are smelling even worse than before the leak was fixed. My whole family is getting sick and we are being put off by the plumber. Should the smell be gone away by now 4 weeks later. And is their anything I can do myself to fix. I have run a 30' snake through the roof vents and found nothing. Please Help!!

Go to a garden supply store and purchase a bag of quick lime. Spread it around the crawl space where anything leaked out. USE EXTREME CAUTION!
Wear protective clothing and gloves plus safety goggles and do not expose any part of your body to it. Good luck, Tom