P.C.
Oh my goodness!! Your son sounds exactly like my son. My husband and I decided to wait until our son turned 3 to try to have a baby, and actually I concieved the day of my son's 3rd birthday party. It has been a lil difficult but this is what I have done to make things easier for my son. We have included him in almost everything. Landon helps me change diapers, make bottles, pick out outfits, feed the baby, and I even went as far as to have him sit with me while I breastfed (conspicuously of course) and explained how I did the same for him when he was a baby. This is one thing though I haven't budged on as far as our old routines go.... Landon's nite nite time is for me and him only. No baby, no daddy, just me and him. He takes a bath, we brush his teeth, I read him a book, and sing him our nightly song (the same song since he was born) all without talk of the baby, or without the baby's presence.
He has had some small issues realizing that when I am breastfeeding the baby, I can't jump up to get him a water or something he wants, but I make it a point to remember every request and get it for him within reason. I have been pleasantly surprised with my son's behavior. He is the absolute best big brother I could ever ask for. He is completely into his lil brother, plays with him, talks to him, sings him lullabys and wants to do everything with him. My husband and I like to think that the way we have handled the "mama's boy" situation has influenced his recent behavior and I hope that my advice can help you in some way. I still tell Landon everyday, a few times a day that he is my world and that noone could ever replace the place in my heart I have for him. If you have any other questions, (not like I am a pro or anything) or even if you just wanna talk, don't be hesistant to shoot me an email and I will help you in any way I know how.
I hope all works out for you and good luck on the baby front.
Pamela
P.s. I never sing the same songs to the baby that I sing to Landon, I tell him that those are me and his songs.