Sleep training LO with Asthma?

I also have a phlegmy, vomitty baby who would projectile vomit at the drop of a hat, so controlled crying was out of the question for us.

I eventually found "The No Cry Sleep Solution" by Elizabeth Pentley which saved my sanity.
Just don't expect it to happen in a week, this is a slow, gentle process that recommends that you regress to a previous stage when baby becomes distressed.

HELP!!!

I just do not know what to do and desperatly hope one of you will be able to give me some useful advice

A bit of background:
My 18 month old baba has asthma - when ever he gets too upset, his chest gets very tight and he starts vomiting. Needless to say, this puts me on high alert since he has been in hospital due to an asthma attack.

However, he now knows that Mommy gets super worried and that I take him to bed the second he moans even slightly ... This is my own doing for allowing him to sleep in our bed - but I couldn't help it. (secondly, he is very prone to ear infections - so every time we get a bit of a routine going, an ear infection will take us back to square one)

Now he wakes up every night around 12 to 3 in the morning. Insist on sleeping with us and then continue to roll and sit up and moan and climb all night long. He does not have a good nights rest and needless to say, DH and I have not had one night of sleep for the last year. It is getting worse and worse

So here is my problem, I want to do sleep training, but I am paranoid that he will get an attack and I will not know? Secondly, a couple of min crying ends in vomit and that stresses me out since I don't know if he is just upset and if it is his chest?

Mommy, Daddy and my little one needs rest - but what to do?

Does anyone have any ideas? PLEASE PLEASE PLEASE HELP!