A horrible moment

I just had a horrible horrible moment. I have no idea what is going on with my kids and their self destructing at the moment. What next??? I am half expecting a broken leg by Christmas!!

Milly has been a bit clingy today - not a big deal. She is going through a clingy phase. She is not happy unless she is on my hip. Awwww, loves her Mummy. Anyway - after feeding her some lunch, I cleaned her up and laid her down in her cot for a nap. She was grizzling the whole time, and I thought it was tired signals. As soon as I laid her into the cot she suddenly started to scream - and she did one huge long scream - I picked her up straight away and tried to soothe her - all the air left her lungs... and she didn't inhale again. But she was still "trying" to scream - no sound coming out of her.. I started to pat her back talk in her ear, telling her to breathe... she turned a horrible shade of purple - then blue.
"MILLY BREATHE!!" I was getting frantic, and I was hitting her back, not sure what to do to get her to inhale. Her eyes rolled into the back of her head and she slumped unconscious. I quickly changed position to support her limp body.
"MILLY!!!!!" I was yelling in her face.... Thankfully she inhaled while she was in that unconscious state, and she came to a few seconds later, crying.

She howled and howled... I sat in the rocking chair with her, too scared to put her down again. I rocked her until she was in a deep sleep, then put her into the cot. Poor little mite..

I never ever want to see that ever again. I might give the parent helpline a call to find out what I can do in that situation. That was soooo scary!