CityMonkey - this is a bit off topic, but who knows, maybe you will find it helpful. From the name, you're obviously in the City. I've seen a couple of your threads in this area and I'm guessing you're a lawyer, right? Probably magic circle or thereabouts? If I've got that totally wrong, ignore me (although these comments will also apply to other professional services). I am a lawyer too.
Your training tells you that whenever you find yourself in an unfamiliar situation, you analyse the hell out of it until you find 'an answer' or 'a strategy'. You collate all the facts and then you make an informed decision. You are always calibrating your facts against other similar situations to see if you need to change tactic.
You are also taught to behave in a 'hurdle' fashion. Your education, your training, your deals. Each is a target, which you work towards, put in the hours, and 'hurdle'. Then you rest for a bit (longer if the economy is slow, less a few years ago
) and prepare yourself for your next hurdle.
It sounds to me as if, naturally enough, you are applying those mentalities to parenting. Please stop. It will drive you demented. If I am speaking totally out of line, feel free to ignore me. But you sound a lot like me, and like a lot of my colleagues, in our first months of parenthood. I didn't enjoy DD1 as much as I should have for that reason. It takes time to learn to chill out, go with the flow and just be still. I'd recommend the book 'What mothers do, especially when it looks like nothing' by Naomi Stadlen for a different perspective on the whole business.
Oh, and on the sleeping, remember other mothers lie. Shocker I know, but they do. Your son sounds normal, bloody good in fact. My DD2 is four months old. She sometimes does a longer stretch at night (four to five hours, but sadly not when I'm in bed), but mostly it's 2 hours day and night.