This would be a perfect question for the Ask A Pharmacist forum:
http://www.medhelp.org/forum_disclaimers/show/296
Otherwise, contact your MD and let them know how much trouble you are having. I've been on certain inhalers that actually triggered bronchospasm, and maybe you are having the same problem.
Do you have nut or soy allergies? Combivent should not be used by people with those allergies.