Sounds like you might have to resort to solitary confinement! ;) My sister had such bad asthma as a kid, whenever I had a cold, my Mum used to make me wear a surgical mask around the house - which was a lot of fun when you can barely breathe out of your nose to begin with! I'd suggest plenty of Vitamin C and keeping your bedroom window open to keep the fresh air circulating (if it's not too cold!) I hope you manage to escape the dreaded lurgy!

PS - if you randomly receive three copies of this comment, it's because the first two didn't seem to post properly!