feeling iffy and mouldy

Feeling a bit iffy this past week.  With the cold snap, getting down to -32°C (-26°F), condensation collected on two walls in my room.  With my bed pushed up against the walls and the storage area under (in) the bed full of stuff, no heat got back there, and this condensation collected, froze, collected more, and eventually grew mould on the bottom 6 inches of the walls.  I was headachy and hacking away for the good part of a week.  I happened to notice a little pool of water at the head of my bed.  Oh crap, where’s this coming from?  I pulled the bed back and found a black mouldy surprise.  It’s pretty much cleaned up now, but I’m still a bit achy.