I keep getting sick from cold nights!?

I had bronchitis about a month ago and was very sick and I just started to get over it. Everything was gone, the sore throat, the runny nose, my voice came back but I still had the cough. It wasn't too bad but certain things would irritate it such as the smell of certain foods that I was cooking or perfumes being sprayed. Well last night I turned the thermostat down a little bit and this morning when I woke up, my nose was runny, my throat was sore, I started coughing and now my voice is starting to go as well. Now, this doesn't happen to my husband and I'm wondering if I'm just sensitive to the cold. I don't have insurance so I don't go to the doctor, but when I was younger the doctor told my mom that my lungs were weak and I was susceptible to getting bronchitis. But I thought this would go away by now, I'm 25! Someone told me a humidifier would help, because maybe the air in my home is dry and is causing me to get sick. Does anyone have any idea if this would help or what would help? Even if the thermostat is higher, I still wake up a little sick, now that the weather is a little chilly outside. My husband has asthma but he doesn't get sick or affected by the temp like me. Sometimes he'll have breathing problems so I'm wondering if the humidifier would help him too.