Sleep talking, walking and many other things

So ever since I was about 12 I started to sleep talk, it started with just mumbling and sitting bolt upright in bed but it turned into actual conversations for example:
One night my mum walks into my room to put some laundry away and I'm sleeping soundly and she opens a draw and I say "don't" and she turns around and my face is turned to her, my eyes are closed and I'm sitting bolt upright. She calls my dad up and continues to put the clothes away and I say "I told you to put it away in the morning!" and my mum gets really worried and goes to the door, leaving it slightly open and I shout "close it!" and several other times things like that happened and once my dad came up to see me sitting bolt upright and mumbling and he said "go back to sleep Sian" and I opened my eyes, got out of bed and walked to the door way and stared out ahead and mumbled continuously until my dad said "go back to bed" and I did. And in Italy on holiday I was sharing a room with my brother and I started to speak Italian (even though I've never learnt Italian in my life) and I got up and bent my knees as if to jump off the bed and onto the glass table until my brother tackled me down back to the bed.
I never feel rested at all, I always feel tired even if I don't wake up in the night (which I also do most nights)
Also one time I had a nightmare when I was ill (always have nightmares when I'm ill) and someone was strangling me and my head pounded and my vision in the dream went and I felt completely numb and couldn't see, hear or move and then I woke up, dripping with sweat and gasping for breath for ages and it felt as though someone had been holding my neck ( I have been held by the neck tightly before so I know the feeling)
Someone tell me what's going on?