I have had very good luck with mine transitioning around 2- 2.5 years. I start trying to get mine in the big bed at least three months before or three months after anything big in the family is happening (especially a new baby). However, if you do not have any major events coming you might want to consider letting him try but not being dead set on it, and waiting a little bit longer, say until three.
Whatever you do you will need to be consistent. So If you don't want to be snuggling throughout the night, you need to have a routine for bed time and then be constant the rest of the time.
What I do is just take their hand,(not carry because then they are getting the reward they wanted) and walk them back to bed and tuck them in with kindness, and leave. Minimal talking the first time if any. and do not hold or rock him. It might take awhile with tiring nights, but eventually he will get it. remember it always gets worse before it gets better. you must do it for at least one week maybe two, to see if it is going to work.
Perhaps you and your husband could take shifts that way you can each get at least 5 hours of sleep if one of you goes to sleep when he does.
You could also get a night light to help with the monster thing. I have also heard of parents using a water spray bottle (monster spray) to dispel any Monsters under the bed or in closets.:)
The other thing I like to do when transitioning is to keep the crib up and in the same room (if you can). I remind them that if they are going to sleep in a big bed they have to be big and stay in bed. I give three reminders (putting back in the big bed), then I put them back in the crib for the night and tell them they can try again tomorrow. Same with nap times.
If you don't have a toddler bed, you could look into borrowing a friends just until he can stay in bed. or look at a 2nd hand store or garage sale. That way you can still use your crib.
when you are fist putting him in bed, it helps to say something like,
"I will be back to check on you in a bit, after I... do the dishes etc... if you stay in bed."
Good luck and may sleep be with you!
E.