I agree that you need a CO detector,anytime you use a heat source that burns anything,you can have CO get to high.
As far as you getting dizzy,have you had a cold or anything in the past few weeks?
If so,that can sometimes cause dizziness later.Had this happen to me last year,I had been sick a few weeks earlier and got up one moring and the room was spinning,I could barely walk.
Went to the doctor and they said that this sometimes happens after being sick.
I was fine after that.
You still need to be checked by a doctor though.