In And Out Of Body, Astral and physical intervention? Options

I recently experienced what appeared to be, another person actually entering my body- my physical body- whilst I lay projecting astrally.
Awoken by pain i found actual evidence of a physical contact at the places where i had astrally witnessed a physical scene.
This left me drained for days- physically- since bruising did take some time to heal. The only clue was that the other body seemed to be trying to wake me up and was explaining that I was looking for her. Does anyone have any resources where I can find out about this, I did not conjure the bruising and am totally sane.
I am new to this site but not to magick theorum and would appreciate magick/scientific/ spiritual/personal advice on this matter since all obe/ projection for me have usually been tranquil, accurate and useful- practical times and this has blown me ;so dramatic and painful experience seems to have no logic.

Sorry I am going on a bit - emails will all be replied to and welcomed.

Floating, feeling light, sense of tranquility will most likely lead to astral projection.
I have experienced it myself and it's very pleasant. You are opening yourself up.
Consider this the first step to your spiritual advancement.
You may feel like you are going in and out of your body. Might even feel a heaviness.
You have to extremely relaxed... I mean really relaxed for this to happen.
Astral projection is when the brain frequency falls between being awake and being sleep.
When we sleep, we dream AND go onto the astral plane where it all happens!
People don't know that but they should.

The mind is the most powerful vehicle, it is the most valuable possession to have.