Experienced chilling sensations when "meditating".

[Swagala]

Last night, I was attempting to Astral Project or at least just practice staying conscious while the body went to sleep. At some point, my body became very still and it felt as if there wasn't even a body, inside and outside felt like they were one. It felt like I was floating around. Then, I started noticing some chilling sensations that started from my lower back and then spread throughout my whole back. It occurred often (or maybe I only ever noticed it when my mind was still/quiet) every time I finished breathing in and then out without having a single thought. I tried to see if I could manipulate where these sensations could spread. I was able to somewhat lead it to a certain direction to some degree. After maybe an hour and half in, I started to focus on my head and then I noticed that I would start feeling the same chilling sensation in my head. I also started seeing some white light. I also started feeling something between my eyebrows which I assumed was this "3rd eye" thing that I'm still not sure what it is about. I tried opening it for a while but at the end, it felt like my whole head was wide open. When I finally decided to end it after 2 hours, it was easier just being instead of having any thought.

For the whole time that these chilling sensations were happening, I was wondering if this was this "Kundalini" energy that I've heard about. But at the same time, there were thoughts of it possibly just being the body cooling itself out.