SiriusStar, I'm just about to go to bed but couldn't not post.
Just a couple of things really.....did you get your PND properly under control after your daughter, or is it something that still lingers, do you think?
I'd second the tiredness thing too - DS2 is terrible when he's tired. Really grumpy, and it's very noticeable. And when he's hungry. When he's not either of these things he's pretty much on a level these days.
But what I find hard is the way he totally wears his heart on his sleeve so everyone in the room gets to experience exactly how he's feeling - brilliant if he's in a great mood as he makes everyone else feel happy too and can really lift your spirits. But he can equally really affect the mood of the whole family if he's not in a good mood himself because he just doesn't seem to have learnt that it's really not ok to complain about every little thing that he sees is not quite right or that it's not ok to make everyone in the room feel and experience HIS disappointment at something that didn't go his way. I guess that's the problem with most of these "challenging" children - they will let you know they are displeased with something. Less challenging ones might just grumble inwardly or just accept the situation and shrug it off.
Sirius, your son will be at school now so could there be a problem at school that you don't know about? My sister also has a challenging one (and an angelic, well-behaved, laid-back daughter, like that from day 1 incidentally!) and he is 6, and until recently your words " cross, unhappy, selfish, disobedient little boy. He is strong willed, emeoitional, flips out over the little things" could have been about him.
Things were affecting the rest of the family sooo bad, his behaviour was making everyone miserable. We were all worried for my nephew because he just didn't seem happy. Eventually, one night he just came out with the revelation that he was being bullied in school. BIG relief from my sister to know there might actually be a reason for his terrible behaviour! She and the school worked really well together to sort it out and he is a changed little boy now. Much happier and much more pleasant to be around, but will still always be able to be described as "challenging" I think!
I think the other thing that helped my sister is really trying to focus on the good behaviours of my nephew. It's all so easy to just be swamped by the bad behaviours, isn't it? And then it seems like a self-fulfilling prophecy. You expect bad behaviour so that's what you get..... so they tried very hard to be over the top in their praise and encouragement of his efforts. They also realised there was a hell of a lot of jealousy towards his little sister, and thinking about it, he might well have had reason to: his sister was so easy from day one, you couldn't help but smile at her all the time and be more willing to interact with her sunny personality over a grumpy, whingeing boy! All the extended family were probably a bit guilty of that to be honest, so we all made an effort to give my nephew more attention.
Lastly, my sis made sure he got more one=to=one interaction with her or his dad, so trips out somewhere with the focus just on him without his sister being there. Even if it was just to the supermarket! More individual attention for my nephew and actually I think it made his good qualities more apparent when they had time alone with just him and so they were more likely to be much more pleasant towards him, and so it starts of a pretty good vicious circle.
Anyway, this was supposed to be a quick one and I feel I've waffled a bit too much.
Hope some of it helped though, Sirius. Just remember to bear in mind the "fantastic in all areas" times when the shit is hitting the fan. It's sometimes easy to forget that those times actually do exist, isn't it?!