Interesting. Everyone's stories make me not feel as bad or guilty when I talk or sit up in bed. I have sleep walked (I guess, slept walked?) a few times in my 29 years, but I occasionally do it a few times a month.
I will wake up next to my fiance, spout some nonsense about what I need to do or who I need to see, get frustrated, and go back to sleep. I usually get annoyed when I realize I cannot do it at that given time or my fiance is unwilling to negotiate. She got irritated at first with me, when he believed me to be awake. Now, she's found a way to talk to me, and to lay back down. It's really weird.
However, she also plays asks me silly questions while sleep talking, and I reply with nonsensical incoherent answers, giving her a good laugh. Once I told her, "Horses don't need umbrellas. Coca-cola has bananas." WTF?! Yea, I know.
I would suggest a psychologist as well, if it's that severe. It comes from a lack of sleep, and internal stress. Do you think laying off the caffeine and alcohol, or even purchasing a new mattress would help?
I've read (from multiple sources, including psychology texts) that sleeping in not ideal conditions can wreak havoc on your duration and quality of REM. An old mattress with worn springs can be hard on your back, and not be conducive to proper rest.
Also, guys, come on! Urinate and don't drink a pitcher of water before you go to sleep!