It's hard to tell where exactly you were. The feeling of heaviness and being pushed inside bed can be just normal thing you experience when falling asleep. Not sure what the darkness was. There is so many different things you can experience.

But the fact that you were aware of all of that is a good sign. It means, that you stayed aware past your normal falling asleep point. Your body was falling asleep and you were aware of that, when normally you don't notice it, because your mind is asleep by then too.

So you are on the right path, keep trying. I'm sure it will work for you.

It's normal to feel scared - afterall, it's all so new to us. Try to have some pleasant thought, maybe an older dream you like, or something cool you want to dream about, or repeat a mantra to keep other thoughts at bay. Keep telling yourself you are at home in your bed, nothing that's in your mind can hurt you. And the HH are all in your mind. It will get easier with more experience. Happy dreams