No, you cannot get stuck in your DR. You can come back anytime you want. Many people come up with a word, phrase, or gesture they will use to return to their CR. They then script that into their shift. That way, when they speak the phrase or perform the gesture, they will automatically return to their CR. Another option is to script it so that you will simply be returned to your CR automatically after a certain amount of time passes or a specified event takes place.