I've been too busy to post lately. I am glad your birth, though section, was better for you to recover from. I hope the mental recovery is also smoother.
I also have a 2 year old. Same thing - DS is so sweet and loving to new DD, but angry at mom and dad (esp. mom). Taken to hitting and biting us on rare occassions. Also now getting up at night and one of us has to go up 4 or 5 times to put him back into bed (which he does willingly, but when he wakes he won't just go back to bed by himself. He did this before, all the time, before DD was born.) Yea, lets have a 2 year old siblings group post!