Hi Sarah,
I'm responding to your candle post. I guess this may sound obvious, but I'd think you wouldn't want to burn those candles again! I've never heard of that happening with candles but in college I used to go dancing a lot in small smoky bars and would blow my nose and have it come out black, so it's probably not a good thing to burn those things without adequate ventilation.
As far as worrying what you inhaled, you can think of it as "did other people in the house feel 'poisoned' by the candles?" If not, then - and I know this is easier said than done - you probably don't have anything to worry about. But as far as worrying about inhaling other things in the past, I can't say, but I'm assuming that you've not spent most of your life working in a coal mine, being exposed daily to asbestos, or spent your youth sniffing model glue or anything like that.
I don't have OCD, but I do worry when I'm exposed to weird smells/fumes - the other day at work we had a minor electrical fire that permeated the office and I was getting worried about it, but then I kind of noticed that the people who were a lot closer to it than I were going about there business not bothered at all - that made me relax.
Well, I hoped that I helped a little bit, or at least distracted you a bit whilst I babbled on. :)