Sleep and Boobs

Sleep eludes me. I don't know if this is the '4 month wakeful' that everyone on the bump dreads, or just a funk, or a major phase of suckage- All I know is it has been about a month of it. Last night B slept from 9:40 - 5 am after screaming for 2 hours trying to get him to sleep. Wow, doesn't sound bad- Well the night before he was up at 1:30, then 5, then 7. So when he slept straight to 5 my boobs were exploding. The night before he woke at 2:15 and was up until 4:30, and I could go on and on and on about random wakings and inconsistency. I keep telling myself it isn't that bad, it isn't that bad, but I wish there was an end in sight. And I also wish I had the magical answers to these questions.
* should we start some form of CIO to teach him to sleep or wait to sleep train? (we have 2 vacations coming up and I feel like we should wait until after so that we can be consistent and not have to start over, but that would be waiting a whole month).

*Should I feed him when he wakes? (My pediatrician said to stop :( However- he is genuinely hungry a lot of the time. I have thought about rocking him (and I do if it has only been an hour or two since he went down, but when I pick him up he is immediately rooting and making the fish face at my boobs). Also- it is much easier to get him to sleep if I feed him, so it saves me.

*How long do I let him gab before going to him? B is not so much a screamer- he doesn't wake up crying. He grunts, groans, moans, and complains. I keep trying to wait it out and see if he falls back asleep- but it goes on, and on, and on- for 20+ minutes (and then I give up and go in). Once I let him go 40 minutes (again he isn't crying, just grunting) and that is when he started screaming and was up for 2 hours in the middle of the night. So am I screwed by going to him after 5 or so minutes when I am sure he is up (and I can tell he is awake), should I let him gab it out and hope he learns to fall asleep, what to do?

*When do I know he is up for the day, or try to put him back down? B usually gets up for the day between 7:30-8am. Well one day he woke at 6:30. He was impossible to get back to sleep, but miserable to be awake. What magic time do I just say ok, he is up for the day versus trying to get him back down.

*should I be feeding on a schedule? I feed on demand, or kind of when I want- I nurse one breast when he wakes, then an hour to 90 minutes later nurse the other side so he falls asleep into a nap. I nurse randomly throughout the day- sometimes it is every hour (although not often- usually only first thing in the morning and then at night I nurse before his bath then before bed) - sometimes it is 3 hrs, usually it is about every 2. I read all this stuff about your LO should eat every 3 hours, 5-6 feedings a day. We are on no feeding scheduke and I often only do one boob at a time. Should I start trying to make a schedule? Wait longer for cues? Try both boobs at once? Or go with it since it is working for us? (or will that screw me up down the road)
That is all for sleep.
Here are a few pictures for fun-