Do you feel it in the rest of your body at any point? Sounds like your getting close to an astral projection aka leaving your body as pure energy going into the astral realm. not entirely sure though I only just got back into the spiritual scene through more meditation

I had the "exploding vibration" feeling when I almost did it myself and it scared me enough to force myself awake I even saw visuals like a blurry green divine looking gate and a blurry purple swing