Awww hun I think you're an awesome mummy and you and your DH are a great team. DD is a high energy kid and DS is normally a cruiser. Today just sucked but tomorrow is another day. I was thinking the same thing as SS in terms of a wonder week for DS (there's one around the 12 week mark I think but your DS could be a little early). I was also thinking along the lines of Marcellus - you're in good company with kids who don't sleep well during the day or want to go down on time at night.

I think DD is probably feeling a bit insecure about her relationship with you guys since DS arrived. She's seeking reassurance, even by saying no ALL the time and being mean to DS. Are you guys trying to get regular one on one time with her? One thing that worked recently with DS's night waking was to stand or sit in the doorway of his room with our backs to him. Sounds horrible when I write it like that but that was after lots of cuddles etc and he was still standing up in the cot and screaming. He settled down when we stood in the doorway and gave verbal reassurance when needed but he wasn't being stimulated by eye contact or having us too close etc. I know your DD is in a bed but maybe something along these lines would help reassure her that you're still around and able to respond to her, even though (she knows) DS also needs attention at night time?

Take it easy on yourself hun. Today wasn't a great day but it's not really a reflection on your mothering skills. Bad days are part of the package. FWIW, I have also whacked DS's head a few times in the car when feeding him and regularly feel like I'm going a round with Jean Claude Van Dam when DS is on the change table. I hope tomorrow is a much better day for everyone.

ETA: Snap olive. Well, not really, I was agonising over my words and you posted pretty much what I was trying to explain!