There was a lot in the last page I wanted to respond to. Let's see if I can remember all I wanted to say... Forgive the fuzzy mommy memory!
CookAMH, rooting is a reflex so sometimes even when baby is not hungry he will root. Both my DS and DD (who is now 3 weeks old) would root anytime something was near their mouth. Putting DD up on my shoulder is guaranteed to make her root, even when her belly is full. Same goes for when I put her up to my chest to wrap her. She seems to root around an extra lot when she is really tired. Sometimes when she is really tired and I wrap her I have to turn her head to the side and hold it there while I pat her back until she falls asleep, otherwise she just tries to eat my shirt (even after a full feeding). To burp DD, instead of putting her up on my shoulder, I sit her up, lean her forward, and cradle her chin in my hand while patting her back with my other hand. This gets the air out but doesn't cue her rooting and frustrate her (and me!). DS had times like you are describing with your DS, where he seemed to want to eat (or suck at least), but would get really upset when I tried to feed him. He wouldn't take a pacifier and only wanted me, but would get really mad when my milk let down. It thankfully only lasted a few days, maybe a week or two at the most. During those times what worked for DS was either a warm bath or my DH would hold him and and walk with him, rocking him up and down in his arms.
And I agree with what everyone else has said about not watching the clock for his feedings. He'll eat what he wants when he's hungry. Try not to worry too much about how long he nurses for, or if he takes both sides. DS never took both sides at a feeding after my milk came in until my cycles returned (about 14 months post-partum) and my supply dropped. DD occasionally will take both sides now, but usually she is done after one side. It's hard not to worry, especially when everyone always asks about how often and how much they are eating, but really try not to pay too much attention to a "schedule" this soon.
pinkersmommy, I don't know anything about the fontanels issue, but try not to freak yourself out. I have learned that nothing good ever comes from me googling medical issues! My midwife mentioned something to me in passing at one appointment about a possible issue I had, and I went home and googled it, and it totally devastated me! It turned out to not even be an issue and I had totally worked myself up over nothing. Everything is so gloom and doom when you google those kinds of things. Try not to stress too much until you figure out what is really going on...
For those dealing with possible food sensitivies, the easiest thing to do is an elimination diet (okay, so it's not easy, but it is worth it to figure out what's happening). Your baby could be reacting to something you are eating, or it could just be trying to get its own system worked out. I tend to agree with what kellymom says, that true food sensitivities tend to be a lot rarer than most people think. If you find something your baby reacts to, of course cut it out, but if not, eat what you want (healthfully of course). Some babies just need more time for their digestive systems to mature. I did several serious elimination diets with DS and nothing made a difference. It turned out he just had reflux. Nothing that caused him to lose weight or have any real discomfort (other than right before he spit up), but he spit up a TON, all the time. I get so tired of people telling breastfeeding women they can't eat spicey foods, or to avoid cabbage, or whatever, because most of the time it's just not true, and I think that really makes nursing seem like more trouble than it has to be. Like I said, if you find something that your baby reacts negatively to, of course don't eat it. But otherwise, you really can eat what you like and still be successful at breastfeeding your baby... Okay, done with my tangent.
For those asking about birth control options, not sure what we'll do here. We've used condoms for the past...7 years I think? because we both hate hormonal birth control and what it does to my body. We won't ever use anything hormonal again. We're thinking about the copper IUD this time around, but I haven't done a lot of research into it yet, so I don't know. I don't hate condoms, but they do make everything less pleasurable for me, since they tend to dry me out and I don't like all the friction they cause. We'll probably just stick with condoms unless I find some compelling research to turn me on to the copper IUD (and as an aside, anyone know if you can use a copper IUD with a Diva Cup, because there is no way I am going back to tampons or pads, ever...?).