A.G.
I agree with the other response. My first son was 6 when my second son was born, and I was on bed-rest for 4 months. I was terrible about involving him in getting ready for the baby simply because I felt so sick and tired. Anyway, we began having the same issues you are having, so I started making a concerted effort - trying to include him more with baby stuff (before and after the baby was born). It helped tremendously. He just needed more attention, and I realized how much I had been needing him too. I really missed the one-on-one time with him after the baby was born. Involving him with the baby was wonderful though; now my boys are super-close at ages 11 and 5. Enjoy your growing family! :-)