Re: Introducing foods at 4 months?
Good advice from the PPs. I just want to add in what my pediatrician would say about solids: until age one, they are just for fun. Until around the first birthday, you want your baby to receive the majority of his nutrition from breast milk, because it's the healthiest, most nutritionally complete thing any of us ever get to eat, and it has everything a baby needs to maximize growth and development. When you compare that to banana or rice mush...
So if you do decide to offer solids, you want to offer small amounts, allowing the baby to gain experience with new motor skills, tastes, and textures without replacing breastmilk in his diet. At 4 months, I personally would not offer more than a teaspoon amount per day, regardless of whether you spoon-feed or take a BLS approach. (BLS rocks! )
I can totally relate to your exhaustion. Both my girls have been around 18 lbs at 4 months, and I always felt drained by that point! But looking back, I feel like what was really draining me wasn't nursing. It was their other needs, particularly their need to be held constantly and to nurse all.night.long.. If night-nursing is getting you down, I suggest checking out Elizabeth Pantley's book "The No-Cry Sleep Solution" for a realistic look at infant sleep and for gentle strategies that can help you encourage longer, more independent nighttime behavior.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"