For the last couple of years, I've been smelling two persistent odors.  
Prior to these I smelled a moldy odor, which went away after cleaning
out a few sinus infections (with possible fungus infections).

The first new odor smelled something like eggs & bacon frying in a cast
iron pan.  This was the same odor as some fungus growing around a leaky
water heater.  When the heater was replaced & the mold removed, the odor
subsided, but has now come back a bit different.

Now it smells more like when cooking chocolate.  I often have overtones
of smoke of all kinds: cigars, fireplaces, etc.

The smells will intensify outside of my home, even on a trip when gone
for a few days.

Do others smell persistent odors like this?  Is there any correlation
between these odors and fungal infections, etc.?

TIA,
Sam