This scenario happens in spits and spats, it isn't constant but it happens on a regular basis. To start with I do sleepwalk, and on occasions have hurt myself, once almost fatally from falling down stairs. Nowadays I lock my door with a key and put it somewhere else as I won't go and find the key while sleep walking.
When I was younger I used to suffer, on rare occasions, from what gets described as sleep paralysis. Couldn't move nor speak. As I have gotten older just of late, surprisingly after moving to a new place, that is an old place it has started happening again, but different. Now I am finding I wake and feel somewhat lucid and can hear noises and then I go to get out of bed, but struggle to move, like there is a weight upon me, like something holding me back. I can eventually get up out of bed and walk around the unit looking for the noise and see nothing, BUT, while I am walking I am struggling to move, it's strange it's like there is this weight down upon me, I eventually am able to say something and inevitably I shout out "F^%$ Off" and leave me alone, I think I say that because I feel there is someone else, maybe that's just what my brain perceives with me waking to a noise. I don't know if I am am being targeted by some being or if it is a sleep disorder of some sort but it is driving me nuts. Damn I am an analytical logical sort of guy, I am an IT guy, I don't believe in god nor spirits for that matter but this thing is getting to me. Just last night I had this again, and as I cursed I managed to switch the light on and heard what sounded like, I dunno, a gecko rapidly making a sound, damn eerie I tell you.
I don't tell people this of a norm in normal day to day life they probably wouldn't look at me the same way again.
That panicky feeling you're talking about isn't just the result of sleep paralysis. It's the result of being in a semi-conscious state when sleep paralysis is still occurring.
That lucid state you're talking about is a state of semi-consciousness. I think this is when most people lucid dream. I know that's when I lucid dream.
I haven't heard many people describe an experience like yours. I actually have one very similar, though I am aware of the fact that I'm dreaming. I know that it's not being caused by an entity. But it's pretty scary all the same. It's most scary for me because I actually can't breathe for what seems like a long time (it may not actually be that long, but it feels like it is).
There have been myths where this experience is believed to be the visitation of a demon. So evidently it's common to get the sensation of evil. It seems like someone said this is caused by the feeling of vulnerability this brings about. For what it's worth.