Hi K., this issue was a big one for me and I believe it changed my whole experience of parenting. If my second child, my daughter, had been my oldest, my whole parenting experience would have been a lot easier, and a lot more fun. People who don't experience sibling rivalry for years and decades have no idea how good they've got it.
It's good that you are trying to give him lots of attention and love. I would definitely stop trying to get him to be with you and the baby so much and instead try as much as possible to get alone time with him.
Go out places with just your oldest boy. I know that is REALLY hard to do with an infant, but get someone to take the baby, even for an hour. Say things like, "let's get away from that baby and go somewhere, just you and me." Don't try to get him to like the baby. The more you do that, the more he'll dislike the baby. (Imagine someone you dislike and then imagine someone trying to tell you all that person's good traits, and how that would piss you off even more.)
I have written a few posts about reflexive listening, or "mirroring", as I like to call it, and basically the idea is that if you "mirror" what you think your son's emotions are, e.g. that the baby is a pain in the a--, your son will actually start to like the baby more than if you try to convince him how much he should like the baby.
I learned that technique too late, from a speaker at my kids' school, but it would have changed everything.
p.s. Theresa B. said it EXACTLY right. The second wife analogy is a good one. Listen to her!