Help -Nap Advice

I just put my 5.5 month old in his crib in an attempt to get him to nap there. I stayed in the room with him, reassuring him every 5-10 minutes. He cried for an hour. I read to pick him up after an hour. Should we repeat the process again at his next nap or only try one time per day? He is 100% reliant on me to go to sleep... on my body, either nursing or sucking one of my fingers. I don't know how to break him of that, other than cold turkey. Should I hold him to sleep first without the sucking? Then attempt put down in crib? Or do it all at once like ripping off a bandaid?? What has worked for you all? He has been cosleeping at night, too... So we are going to work on sleeping in the bassinet. Again, not sure if I put him down awake and let him fuss for ages with reassurances or if I let him sleep on me and try to place him in. This sleep stuff is hard and I don't want to traumatize him. Picture bc he is adorable. 😉😉