Magic Sleep Suit for 9 month old

My baby is 9 months old and still doesn't sleep through the night, in her crib or anywhere other than mine or my husbands arms. She won't lay flat on her back and hasn't since the day she was born. When she's sleep in our arms and we try to lay her down she does this thing like as she falling in her sleep and wakes up instantly. It's like she knows we are going to lay her down. We've tried everything! CIO, waiting until she's in deep sleep to lay her down, rubbing her back or tummy, walking in and out of her room every 5 minutes. Nothing will work. If she's not in our arms she will scream and cry until we pick her up. Can I use the Magic Sleep Suit? Or another weighted Sleep sack? Or is she too old/big? She's only 17 lbs and I know she likes warmth and to feel secure but she can't be in our arms 24/7.  I'm all out of options. 
***For those saying I should discuss this with my pediatrician, I did. her advice: Let her CIO, check on her every 3-5 minutes, when she wakes up give her water, don't breastfeed, let grandparents watch her at night.