It's not you. It's the milestones. What I am about to suggest is not BW approved, so take it with a grain of salt, but it worked for us when nothing else did. Do solids before your bottle. Wait about an hour to an hour and a half to give the bottle after solids or do it right b/4 naptime. It calms him down, fills his tummy. Isom almost always falls asleep on the bottle, BUT he also wakes when we put in the crib, looks around, grunts (like oh, okay, whatever) and passes out with his butt up in the air. He sleeps at least an hour for his naps that way. I was having the same problem w/ naps and overtiredness, and I put him daycare. They started feeding him the bottle b/4 naps, and viola! a perfect napper. I know it doesn't work for everyone, but it seems to be what Isom wanted. Everybody's happier, so we're just going with the flow.
Let me reiterate, though, if you keep with the BW method, it will get better - he's just learning so much so fast it's disturbing his sleep.
Good luck,
Crystal