LD, Sleep paralysis and sleepwalking

Hi all,
I'm completely new here, have done some research, but am missing " the link" somehow. Maybe one of you can help me figure out what's going on in my sleep?

First of all, I guess I have experienced some sort of sleep paralysis - it keeps happening when I'm lying on my side, having a nap - my body goes rigid, I start hyperventilating, and I have a "I am going to die" sensation, a very fast heartbeat, and panic sets in - I usually try and force my body out of this state, trying to force myself to breathe slowly, and coaxing my body back into movement - I find this state fairly frightening - and this may sound naive, but what is the worst that can happen during this paralysis? Am I awake, or am I dreaming during this state? Is there any way to prevent these feelings, or any way to make it at least more "pleasant"?

Secondly, I sleepwalk a lot - what I've found so far is, that people who sleepwalk can't remember why they did it, and what they did. Now, when I sleepwalk, I know exactly WHY I do what I do in my sleep. The feeling during these sleepwalking periods is almost like I am awake, acting "normally" within the setting of my dream (e.g. I would rearrange the furniture, or pack my bags, because in my dream I am going to travel somewhere). I would wake up and find my bags packed - and then realise "oh, yes, I was going to travel somewhere". And even the weirder stuff I do I can explain. Sometimes, it freaks me out, because I am fully aware that I could do stuff in my "semi-awake" state, that might not be beneficial - has anyone ever had the same experience? Is there anything I could do to stop my body from walking around, doing stuff? And is it normal to remember - as in, shouldnt everyone who remembers their dreams also remember their sleepwalking?

And thirdly, another weird thing (I think it was called "false awakenings" here, but I'm not sure if this really applies): following examples I am in bed, and I *think* I am awake, say in the morning, just before the alarm goes off. I move, to change the alarm time to have ten minutes more sleep. I move my body, I move my arm, I set the buttons on the alarm, check that the time is correct, and go back to sleep. I wake up with the alarm clock going off at the correct time (not the one I've "set"), with a really confused feeling that I changed the clock, and changed it consciously. So I guess I must have been dreaming, but the whole thing was so real! Would this classify as a false awakening, or is there any explanation for this extremely vivid dreaming?

Oh, and I almost forgot this one: sometimes, when I am falling asleep, I have a falling sensation (someone in this forum mentioned that the sensation of gravity is lost or something to that effect), followed by some sort of "crash" in my head - like something from the inside is trying to escape through my skull. Has anyone ever experienced that before, or has a reasonable explanation?

I know, these are a lot of things at once - but after I found this forum, and had a good read, I think I am not alone with all these sleeping "disorders"! Your opinions would be greatly appreciated!

All the best and sunny greetings from Ireland
galah