Can't get from SP to LD?

I can consistently hit SP now, I usually do at least once every morning I try to.

I usually will get the vibrations and the spiked heart rate (though I don't usually get any hallucinations of any sort). Unfortunately, regardless of what I try to imagine, I'm not actually getting to dream state. It's like I just sit there with vibrations for 15 minutes, and then give up and deep-breathe-exit SP.

One time I think I did get to dream state, (or at least the vibrations stopped and I kind of "shot forwards" into this black spot in my head). I was fully lucid, but I couldn't do anything. I'm not sure if it was a dream or not. I tried to make some surroundings, but it was like I didn't even have a body. Everything was just blackness, and after a few minutes I just woke myself up because I wasn't getting anywhere.

So what am I missing here? Doesn't dream state naturally follow SP?

I have the same problem. I mentally pat myself on the back every time I get to that point, but I don't know how to get past it. I usually end up rolling over and falling asleep, hoping I just have a DILD.

I could have written your post. I have the exact same problem, heart rate spike and black abyss included. Just can't seep to get further and I don't know why :(

I also fail at transitioning. Everytime I try to picture the dream I wake up.

Basically, I started naturally lucid dreaming before actually knowing about their existence, also I would suffer from SP, It would be horrifying for me because all I wanted to do was wake up/move and I couldn't. When I googled about SP I saw I could use LD'ing as a type of "Therapy" for my SD attacks.

A few tips to follow:
Stay Relaxed.
Close your eyes and just keep trying to picture a dream, don't try to move and don't open your eyes.
Once you are sure you are dreaming, what I usually do is try and open my "dream eyes"
Stabilize the dream if necessary.