Tracheostomy and constant infections

I am a Tracheostomy patient and have had a Trach since August 2008 due to removal and treatment of Thyroid cancer.  The procedures rendered my vocal chords paralyzed and me unable to breathe.  So I needed a tracheostomy.  Since the trach surgery I have had an almost constant case of Tracheitis... It happens after everytime I catch a cold.  I think I have only had two-three weeks of feeling healthy since August.  Does anyone have any info on prevention of this infection, any advice would be helpful. I am extremely clean when I am caring for my trach, and very mindful of staying away from situations that might make me sick.  The infections get to be very painful, cause me to lose sleep and cough up blood because all of the stress of my lungs trying to get rid of the infection.  I constantly feel run down all of the time. Should I also be worried that I may have contracted MRSA and that it may not be Strep that I am dealing with?

Thank you-

Shay