PleaseI'm a couple years late, but if anyone has this issue please look into it ASAP! Sulfur eating bacteria could be present in your water. Look into how old your water heater is and whether it's overdue for replacement. Recommend a new one every decade.
I recently had the same exact issue with my condo's laundry room where the water heater was located. Smelled like something burnt/of cigarettes and over time smelled increasingly bad to the point I had trouble breathing and horrible congestion. Thought it was a flu. My heater was old and once it was replaced, the smell went away.
However if you discover your water heater is less than 10 years old, call a plumber and let them know of suspicious aroma. And they can drain the water, chlorinate the tank to kill off bacteria and see if smell goes away.
Long-term exposure to hydrogen sulfide gas is dangerous to humans and pets. If you can't escape your home immediately, then keep fans on and windows open. Recommend every household to have a gas detector to monitor air levels