DS is 4.5 and has been using a nebulizer since he was 10 months old. It took him a long time to get used to it. When he was very young I would have to wrap my legs around him to keep him in place and he would cry the whole time. Eventually, as he grew and got used to it, we settled into a routine. Around age 2 or so he started to get really good at sitting for his "treatment". He had a special place to sit and a special show to watch on tv. Now he's an old pro at it.
I agree with all of Fairy's advice in her post. (Except that the purple dragon mask fit DS well when he was really little, but starting at age 3 the blue and orange fish mask fit him better.)
It really does get better. It just takes a while. It's really hard when they are little, but eventually it just becomes another part of the daily routine.
Good luck!
Gena
DS, age 11 and always amazing
“Autistics are the ultimate square pegs, and the problem with pounding a square peg into a round hole is not that the hammering is hard work. It's that you're destroying the peg." - Paul Collins, Not Even Wrong