Help!

Recently switched my LO to a sleep sack because she’s been moving a lot in her sleep and I keep finding her in a different position then when I put her down. I have a sleep sack from carters that has arms out, which I’ve only ever seen ones with arms out. But she keeps startling herself awake. Idk what to do, she won’t get sleep and neither am I. She wakes up every 10 minutes from startling.