I know how frustrating it can be when our children's sleep schedule changes...just when you thought you could sleep through the night - yes? :)
My question for you is, why do you feel that staying in his room during naptime is not good? Is that something you really feel strongly about, or are these judgments based on what our highly independent culture says about it? The reason I ask is so that you really do what YOU FEEL in YOUR maternal instinct is best for YOUR child. Check in with your assumptions on how you really feel about it (or any other parenting matter). It's the only way you can parent in your own truth.
My suggestions? He is only 2. Going from a crib to a bed is a BIG transition for him. Even if he did sleep through the night for the first few nights, waking and wanting to be with mommy and daddy is very very normal. HE just wants to feel safe:) What is his bedtime ritual like? When children have a pleasant experience with going to bed, it's less scary. Keep it simple and consistent.
You will probably have to keep taking him back to his bed every night for a while before he gets used to his new big boy bed. It's not easy...you are tired, I know. Be patient with him. It will pass.
As far as naptimes. Did he start this new thing of not napping before or after he moved into his bed? If it's after, then I'm sure it's because of this transition.
As far as staying with him while he naps? How about sitting on his bed reading a story for a while until he falls aslepp. Then you sit in a chair next to his bed for a while. Eventually, he will fall asleep on his own. You can probably try rewards for going to sleep by himself...but really, toddlers are IN THE MOMENT little creatures:) Us thinking that he will sleep now to get a goody later??? Isn't very realistic for 2 year olds. (I'm not a big one on rewards, but that's me). Or if you really don't have an issue with staying with him, why not try just laying down with him and having some snuggle time and getting a few zzzz's yourself? I'm thinking that he just needs a little reassurance now....the best way to give that to our precious wee ones? Love and attention - but you know that:)
Much good energy to all of you for sound sleep.
A.
Mom of 4, birth and parenting mentor.