My daughter was the same way. She was an excellent sleeper, then right before her 2nd birthday she freaked out and was afraid to sleep in her room. Fortunately, I took the advice of a very good doctor who put it into perspective for me. There is nothing wrong with having your child sleep in your room. Only in North America are we soooo concerned about having our children sleep by themselves. In some countries whole families sleep together for years. The children turn out to be confident, loyal and caring. The world is a scary place for a 2yr old, especially when it's quiet and dark. In the end, I put a toddler bed in my room and my daughter slept in our for a year and a half. Then we decorated her room into a big girls room and she's been sleeping there ever since. She's six now and every once in a while gets scared and askes her father or I to sleep with her. And we do, b/c we've realized pretty soon she'll be kicking us out of her room, and I think we'll be the ones crying.
Good luck.