When can I get padding for baby’s crib?

So here’s my story I’m a FTM and I love my baby and since I gave birth until 6 months have always been afraid of SIDS. I even got baby the newton mattress, no pillows,no blankets, not even while supervised! Anyways my daughter had to wear a doc band since 3 months until 9.5 months. But at 3 months she wasn’t moving as she is now, ever since we got her band off it’s been hell she wakes up between 4-8 times everyday!! We are exhausted. At the begging we had no idea what it was we took her to the doctor, until I stayed in her room we have a bed there but she’s been sleeping alone since 6 months. Anyways she hits herself while she’s asleep which causes her to wake up!!🥺 We have been told she’s going to learn and stop but it’s been a month!!😞😔🥺 Can I buy the padding that goes around crib? When is it safe to use that?? Can I? Obviously her safety is my priority but I wanted to check if she can use that already or until when? Any recommendations?

Edit: To add that prior to this when she had the band she was waking 1-2 times max! Please help!