I was trying to project for my 6 or 7th time when I felt like I was going to do it. I felt the vibrations, moving my limbs without actually moving them, the stuff. When I felt like it was going to happen, I felt what was like a punch to the stomach. It knocked the air out of me, and immediately made me lose concentration. I tried to cast a protective circle first if it makes a difference, though I may have failed. Any explanation?
Something else, I tried to clear my head and try again, but this time as I was forming a protective circle, I felt an evil presence, dark enough to completely paralyze me with fear. This is the first time anything like this has ever happened to me. Should I keep trying, or take this as a warning to not try again?
It could have been a being from the astral realm if you feel like you were on the verge of entering it. Beings of positive energy are not the only beings residing on the astral plane. I know it's not usually good to quote movies when it comes to talking about things like this but remember I liked the way they explained it in the movie Insidious, that while these astral beings can be utterly terrifying to us, we have the upper hand because we are human, we have bodies tethering us to this world and our lives where they can't affect us. We have a place to return to, they can't really hurt us even if they might be able cripple us in fear for a while. But Insidious also has a lot of incorrect portrayals of the astral plane, I just liked the way they explained that one thing. If you wish to keep trying to reach the astral plane be aware that you probably will run into beings of a similar nature and to be brave.