Nebulizer medicine makes my Asthma feel worse????

Anyone else have this problem? I'm nebulizing Pulmicort once a day, but when I do my nebulizer treatment, about 6 hours later I have an Asthma attack and feel like I'm drowning. My doctor thinks it will go away after I've been using the nebulizer for awhile, but I don't like waking up in the middle of the night with Asthma (never had this problem with the Pulmicort Turbuhaler - a powder-based inhaler that has been discontinued by the drug company).

Thanks,