Does Advair make our bodies dependent on it?

I've taken Advair 250 for years. It did reduce my asthma wonderfully. However, after not filling a perscription and going longer than a couple days without it, I noticed I was way more out of breath than I used to be before taking Advair. I was forced to continue without the medication (due to money issues) , and my breathlessness cleared up. I was off of Advair for more than a month, and fine. Then, my doctor gave me samples of Advair at a higher strength, 500. I've been using it and I notice that not even 12 hours later I'm out of breath! I just can't breath deep enough. I'm using my rescue inhaler more. I've tried to tell my doctor that I don't feel right about it. His answer: " You have asthma, of course your out of breath" My asthma has always been triggered by allergies. I've never had a constant issue with breathing until I've taken Advair. What is going on? Does anyone else notice this?