hey S.- your letter sounds so much like me 6 months ago!i'd suggest that you really need to start getting a regular routine down for him. it was at about 6 months that my daughter (who was breastfed, co-slept and babyworn) suddenly changed in her sleeping habits and became extremely erratic. She went from going down around 8pm in my arms and transitioning to bed with us, sleeping for 5 to 6 hours and then waking up... to waking up every hour or so, no matter WHERE she was. and her daytime naps were irregular to say the least. I was beginning to despair, as her teeth were coming in, she was crawling AND starting solids, so I knew a lot was going on at once and she was really tired.
My first stop was to the pediatrician, who said that a regular sleeping and eating routine was essential, and that my daughter, at 6 months, did not need to eat at night. So we worked on the night nursing first. It was hard, b/c we co-slept, but finally after repeatedly giving her an empty boob (i'd sneak away and pump, or offer her the one that just was emptied) she got the message really quick. I made sure she had 3 solids a day and at least 30 oz a day (nursed like 4 or 5 times).
Second thing we did was establish a bedtime routine- for bedtime and naps too i stopped nursing her to sleep. I'd nurse until she was drowsy, then put her to bed in her crib for naps. Being in her crib made a big difference too- i wanted her to learn to fall asleep on her own and not in my arms or in my bed. she is easily stimulated, as babies can be, and her sleeping with me nearby was never a deep sleep. It probably took 2 really difficult weeks of her being extremely confused until she realized that being in her crib meant naptime. If she did cry, i didn't let her cry more than a few minutes. At this point I also made sure every nap and bedtime were the same- smae blanket, same lights turning out routine, same lovey in bed with her. I established her naps at being at 8am and 1pm for two hours each, sometimes she slept more, sometimes less. Babies need about 14-16 hrs of sleep a day, which means they can't be awake more than 2 hours or so. Sleep begets sleep, so once he is tired, (rubbing eyes), get him to bed! you really have to be consistent, so that they understand it is naptime. it's hard to do, because sometimes they really want to be awake! but being a parent is about setting limits and enforcing them sometimes, even at this age. it made a HUGE difference right away.
Finally, we tackled night time. I tried to continue co-sleeping but it just stopped working for us, mainly because I put my daughter to bed two hours earlier than before- at 6pm. Sounds crazy? it worked like a CHAMP. Within 2 nights, she was sleeping for 10-12 hours straight. if she cried, i went in and soothed her, (i would let her fuss, but not cry) but for some unknown reason, this earlier bedtime, coupled with a regular daytime routine suddenly "clicked" for her. I nursed her when she woke up in the morning, at 6am. I hated giving up co-sleeping, but she and I and my husband slept so much better when we had our own space, and it gave my husband and I some time alone together, which was really nice! All was not peaches and cream- some nights she was REALLY mad when I'd leave her room... but kids get mad sometimes, and i made sure that i didn't abandon her in her room to cry- but I would let her fuss and sort it out.
And no- the later you keep a baby up does NOT mean they will sleep later in the morning. they are not like adults. so if your son won't sleep past 7... then he's just not going to sleep past 7. 7 is really late for a baby anyway! So that's great he'll sleep that late! Since he needs about 14 hours of sleep a day, you'll have to put him to bed earlier in order to ensure he's getting the right amount of sleep. Right now it sounds that he's overtired, and can't settle himself to stay asleep. That and he needs to learn to fall asleep by himself and not through nursing. he's old enough to be taught how to do this. a lovey will help, as will a routine. it'll probably take you 2-4 weeks to figure it out. Co-sleeping is wonderful and I do miss it, but I realize now that seeing my happy, healthy, well-rested kid that giving it up was best for all of us.
there's just a lot of give and take, and although i thought I was set in my ways and parenting the way I wanted, i realized my daughter was telling me she needed something else for it to work for her. So we slowly changed, each of us, until we found what worked.
phew that was long, but i know sleeping is such a difficult and sensitive subject-what works for someone might not work for you, so the main point is to do what your son needs and be consistent! i wish you lots of luck!