N.P.
Your poor son. As they doctors say, sleep them propped up when they are ill. Okay,yea - how can you do that when they are in a crib. I am a mom of twins... I JUST transitioned my kids to their cribs for their naps and they are 19 months old. So do what works for you. My son sounds a lot like your son and both children could and would cry for 3 hours if I let them and didn't put them in their swings. But as they hit 18 months and the weight limit, we had no choice and they had to get used to it. After a week and a stressful one for mom & kids, they got used to it. I found that using blackout liners helped. Also, when you put him in the crib, if the swing has any music/sounds he is used to, play it for a few days. Good luck and I hope he feels better soon and stays better!