1) try get him used to a transition object ie: a stuffed animal to hold, or put him in a swing. My son also loves his Fisher Price "OCean Wonders" crib toy and turns on the music himself to fall asleep. Or try white noise ie: we have a fan we turn on low when my son sleeps.
2) daycare may get him in the habit of sleeping on his own. A good thing. Tell the care provider of his trouble self-soothing to nap by himself so they know.
3) A baby this age should NOT BE IN A BED by himself. He should be in a crib...for safety. And as you see, even in bed with parents, they can crawl out or fall out getting hurt whether or not you are there. If not, try a floor futon. That way he can't fall out and get hurt... and it can be a good way to transition him to sleeping by himself. Another thing, if he is sleeping on a safer apparatus ie: a crib or floor futon...then when he wakes you won't have to rush in for fear he will fall off the bed by the time you get to him after nap/sleep.
*If he wakes and cries when he sees you are not there... well try NOT rushing in right away...give him a few moments to be by himself... I'm not saying cry-it-out...but babies need time to wake up, and sometimes cry/grumble a bit and then they stop and/or go back to sleep....if you rush in sometimes in between these little cries...it prevents them from going back to sleep on their own and you disrupt their REM pattern. Sometimes, rushing in at every little sound/cry they make, gives them the in-ability to soothe themselves.... sometimes giving them a moment to themselves can give them a chance to learn how to self-soothe. Really "Listen" to his cries... they have cries for hunger, for distress, for when they are in between REM cycles, cries for dirty diaper, cries for when they are wondering where your are as they go through "separation anxiety", and cries for just because but nothing "major" etc. So really evaluate that.
4) Any transition will take time & patience... be prepared for that no matter what method you try.
5) Nothing wrong with co-sleeping, we did that do, and still do from time to time. An alternative can be having a futon on the floor in your bedroom, to put him to bed/nap on... then when he falls asleep, you and Hubby will be right there... but in your own bed. That's what we do. Or sometimes our eldest child still comes into bed with us... it's okay with us.
6) for co-sleeping...it has to be, ideally, a JOINT decision with Hubby. Afterall, a man likes to have his bed to himself sometimes... with his wife. Be sure to consider that... you don't want Hubby to be unhappy about it... or at the worst, resentful of the co-sleeping arrangement.
7) as for having a baby #2... hopefully, transition your baby to sleeping in a crib.....it can be in your same bedroom, but not in the bed. Then when baby #2 comes, it won't be so hard. I know a friend in which they all 4 sleep in the same bed.... but yes it is a crowded situation and tricky, if one baby/child gets up or is fussy/crying.. and this wakes everyone else up. So this is why, I suggest another floor mattress/futon bed in the bedroom as an alternative...that way you are near the baby.... but not exactly co-sleeping...but it's a transition and can be a more workable sleeping situation.
There are many methods, albeit, complicated maybe. But just try it. If you really want to "wean" your baby from co-sleeping, it's just a matter of doing it, and seeing what happens.
Good luck
Susan