Can someone help me understand this?
 

okay so ive been trying to astral project for about a month now and the only time ive ever hit the vibrational stage is when i sense there is something wrong in my dreams. (Nightmare) i only feel these vibrations when i have nightmares. is it my fears? i have already gotten over them.i practice not only in reality but also in my Lucid dreams. is there something im not understanding or something else im supposed to learn how to do before i astral project? Any advice anyone?

Are you sure you are experiencing the vibrations? I know that is probably annoying but you might just be wanting to experience it so you are creating them yourself. As far as your experience goes I can't say much more about it because I have not ever had any scary moments projecting. Only amazing and even miraculous ones. I would guess that it is more telling of an internal issue than anything else.

Vibrations are also the start of your energy leaving the body. It seems frightening when you don't know what's happening.

Assure yourself its normal. After the vibrations things may go "dark" or "black" in your mind and then I hear an audible "pop" in my mind when I disengage from my body.

At first this would startle me back and I'd get so frustrated! lol You have nothing to fear. call your guides and angels to help you and surround you. Even if you don't know their names, they know you. It will help you to feel safer and thus you will AP. :)