2 month old has never slept alone, wanting to transition to crib.

My son has never slept alone. When he was born, I didn’t sleep any because I’d sit him in his bassinet at the hospital and he’d cry after a few minutes so I held him most of the time. He won’t sleep in his bassinet or crib. Or his swing. He’ll sleep in his car seat on car rides, but when I take him out to lay him down, he’s wide awake. I purchased a cosleeper and he used it one night but won’t use it anymore. He wants to be right next to my boob:/ We’ve been bed sharing as that’s all I’ve found to work. I’m worried about sids but I’ve made it as safe as possible, as it’s only the mattress, no box springs or rails, and nothing but a fitted sheet over it and I centered it in the room so he won’t get stuck between the bed and wall. I’m worried when he gets older, even though it’s close to the ground, he’ll crawl and fall off. Any tips on how to get my baby to sleep in his crib?