Supporting kids during a seperation

Hi all. Me and my kids father have been together for 8 years, prior to our split in January of this year.

My daughter is 7 and my son is 5.

We started 50/50 in march of this year.

My daughter’s behavior is not so good. She is mainly talking back a lot and giving attitude to both of us but a lot more to her dad.

I have had plenty of talks with her and I can’t pinpoint it. I don’t know what I’m doing wrong.

I know she might be over whelmed and hurt, but I don’t know what to do..

My son on the other hand, he is a big mommy’s boy. And he is constantly whining and crying for me while he is at dad’s. And it breaks my heart into pieces.

We do the 2-2-3 method, because I thought it’d be a bit easier for them.

I know this is going to be a process for them but I don’t know what else to do other than cry when they’re not with me. I am always encouraging positive attitude and spend as much time with them when they’re with me.

I feel defeated and guilty.