My first question is did you buy a regular mattress for the pack and play, those mats are so uncomfortable!! I purchased portable crib mattresses for the pack and plays at my daycare and the children sleep so much better. Second, what we do verses CIO (even though I did it with my kids) is we will rub their backs, sing to them, pat their bum, but DO NOT pick them up. Even if they are crying, you are right there with them, so you are not harming them, you are teaching them to go to sleep. It works for us. It may take a little time, but eventually they will learn that they are not going to be rocked. Also, do you have a bedtime routine, bath, story, etc. I am a huge believer in bathing children every night, I think they sleep better when they are nice and clean, and also it relaxes them. And do the same, I have music boxes in all of my cribs and pack and plays at the daycare, and I used music with my own children. It is a nice distraction. Do the same at night, I know the crying will bother you, but remember you are not leaving them alone, you are there with them, they are fed, dry, and safe. It took me a long time to be able to do CIO with my daughter, I was sleep deprived for 1 year, she was up 3 to 4 times a night. Finally, I was so tired I did it, it worked, I had no issue with doing CIO and still don't, but it isn't for everyone, and I understand that. Good luck, I know how it feels to be sleep deprived.