gas smell, power loss, high fuel consumption

I have VW Passat, 1999, 1.8L, Turbo; 142 000 mileage. Recently I started to have a problem with my car. There is a gas smell inside and outside of the car. The car lacks power on low and high speeds. It moves very slow and takes more gas than it should or did. The car starts fine.

There has been work done couple weeks back on throttle body, the mass air sensor has been changed. Also I have changed the air filter. The oil change is always done on time and I always use premium/super gas.

Any ideas what can be wrong?