Arms out sleepsack transition

My 4.5 month old is having the hardest time transitioning from having his arms fully out of his sleepsack. He was in the love to dream sleepsack with the arms up. Took the sleeves off to start the transition and it’s been hell 😩 he still gets up as much as he did when he was a nb and now it’s even worse. Any advice? I’m so tempted to just put them back on. I even got the zen sleepsack and that hasn’t helped either. I’m so tired.

Also rotated each arm and neither helped the situation