Will my medication become habit forming?

If you're referring to controller asthma medicine, the answer is "hopefully."  You want to make sure you take all the medicine exactly as prescribed, especially if you are feeling good.  If it gets to be a habit to take your medicine all the better -- that's a great thing actually. 

Or did you mean addicting.  Can you become addicted to asthma medicines?  I have never heard of anyone becoming addicted to asthma medicines.  However, for some people with severe asthma, it may seem they are addicted to their rescue inhaler as they use it more frequently than the average asthmatic.  But I don't think you can become addicted to any asthma medicine.