Why is my asthma getting worse?

About half a year ago, my asthma attacks were VERY uncommon, say, once every 2 weeks.

Now, however, is a different story. It has escalated to many times a week, and my medication doesn't seem to work. It's like, I take the medication, and it will fade, but not entirely. I still have this slightly short breath, a tiny little squeak at the end of each breath. I do not know why my medication does not work;it SHOULD.

Why? Is this because of the weather? (I live in NSW, Australia, and it's currently Autumn.)

Can anyone help? I am desparately short of breath. I have to use my medication AGAIN.