4mo rolling into stomach all over crib at night. Im so stressed!

So we have been successfully sleep training our 4 almost 5 month old. Tonight he started completely rolling over! I AM NOT READY! my husband says he will be fine he's a strong baby. He can roll both ways and can hold his head and turn it to lay both ways but still I'm so ANXIOUS. how do i know he's breathing? how do i know it will be OK? We JUST moved him to his own room. Hes been sleeping in our room in his crib for the first 4 months of his life and every part of me wants to sleep on the floor next to his crib :p

For all the other anxious parents out there what have you done? How have you been OK with this phase? Im just like constantly looking at the monitor and checking for breathing.

He currently sleeps in a swaddelini, here's a link for reference.

https://swaddelini.com/products/grey-arms-out%E2%84%A2-swaddelini-sleep-sack?variant=44868765843701&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&utm_source=google&utm_campaign=20837534616&utm_medium=ad&utm_content=&utm_term=&gad_source=1&gad_campaignid=20837537892&gbraid=0AAAAAoXbRP5_PPac_OiWqX7zxkxjCxrVX&gclid=CjwKCAjwl_XBBhAUEiwAWK2hzs6vieg9t2XGfZS5Ctwgj_EcK9EZ-tbbzIt70k8mSNCfFLRJbJN7IhoCrx0QAvD_BwE

A second question: He is also rolling around the crib and sticking his hands and legs through the slats....What do i do?!?!?! im so afraid he will get an arm stuck. is it enough to just watch and help him when i think he needs it?

Right when sleep training started getting really good now we have to worry about him doing cartwheels in the crib :p Parenting is really something haha.