When my kids did things like this, I know I felt like I was at the end of my rope, too. We actually did use a crib sometimes, but CIO never! When a baby would wake up, not unhappy, but awake and want to play, we would follow the Sears' advice, "Pretend to be asleep." Don't turn on any lights. No books. No playing. Baby can have the breast and lie in your arms or lie and play quietly, but he won't have a playmate at 3:00 AM.
I once found myself "entertaining" a baby at 4:00 AM in the living room, my husband came downstairs and asked me what the heck I was doing. I suddenly realized. "What the heck am I doing? I can parent while lying down." So Baby was swept up, I turned out the light, I refused to play (nicely, because I was pretending to be asleep) she was offered the breast, didn't want it, smacked me so I would play with her, I turned so she couldn't get at me, she tried it again, crawled OVER me and tried to open my eye with her little fingers, I removed her fingers, offered the breast again. Baby finally got it, "She's not going to play with me." Then they would usually either go to breast or lie quietly.
Probably due to a milestone, learning to walk, teething, learning new words. My babies learned, "She doesn't play with us at night." I LOVED them at night, I would hold them and nurse them at night. But, under no circumstance does the light go on, nor do we engage in conversation (other than "do you want the other one?") we do NOT get out of bed and walk around, or play, we lie down, we rest, we nurse, Baby can babble quietly to herself. Eventually they get it.
I empathize, Mama. It can be exhausting, but if you gently pretend to be asleep, and only offer warm arms and the breast, and little to no stimulation, he will eventually get it.