Smokey Smell Inside house

I live in a rural neighborhood on a mountain along a river where people use wood fireplaces as a regular source of heat.

I unfortunately live in the valley of the mountain close to the river. During the winter at night all the smoke seems to settle. When the smoke settles it makes my entire house smell like an ashtray. I can't stand it. My asthma has started acting up again to the point at nights Im having a hard time breathing.

Ive locked all my windows tight, ive sealed my windows with tape along the seams. Ive covered my own propane fireplace. We've resealed all our doors.

At this point im convinced it is my heat pump (electric).

We are about to have a baby and I can't have them breathing in this toxic air all night long. There has to be a way to prevent outside air from getting in the house at night.

The house was built in 2007 so it isnt THAT old. Any suggestions.