Feeling like its laborious to breathe and/or getting "tired" of breathing?

I was diagnosed with asthma about 12 years ago, but I don't particularly remember those symptoms I mentioned in the title. I recently had an onset of my worsening asthma symptoms with a severe sinus infection, but until the last week or so, my asthma has been pretty much under control (only using my albuterol inhailer about once a week). I also take inhailed steroids daily and have been on Prednisone numerous times in the past.

I'm just wondering, are those usual symptoms, or can asthma not cause those? I mostly notice the "feeling tired of breathing" a few hours into an attack if the nebulizer doesn't work. It's like I have to consciously think to breathe, and at some points (when I'm exhaused from days of not sleeping while being sick) I get really dizzy, notice that I haven't taken a breath in in 15-20 seconds, and then get startled and start breathing again (of course, thinking "breathe in" to myself). My chest gets really sore after this because it's such a struggle to just breathe in... and it feels like I can only take a half of a breath, no matter how hard to try to breathe in. Sometimes my wheezing sounds like one of those high-pitched dog whistles, but for the most part, I don't wheeze at all. Oh, and I get a dry, hacking cough too.

Thanks if someone can help because I'm pretty worried about this! :)

http://allergiesasthma.itags.org/q_allergies-asthma_221055.html