Don’t worry. Scary meditation experience can happen sometimes. You describe it as if some kind of entity was coming towards you. I'm not sure if that's the case. When people feel they are about to enter a black hole, lose themselves in it, or actually die, it is usually the old mind structures falling away, or the old personal self being absorbed back into its own source...
Scary Meditation Experience
But recently, last night in fact I was very focused on listening during meditation. As I concentrated on my breath and listening to the silence around me, I felt my eyes became locked, all thought dropped away, I soon entered into a void. I started to feel I was letting go of everything, and the feeling of immense joy surrounded me...