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.

O.O Ive actually done that too. although i was on the other end...and someone received me. its happened twice. Once with a woman who was completely paralyzed, and the other time it was also a woman (i think) who had a friend in the room with her. it was very strange. i had no injuries, but i was very disoriented and panicked for a while. i'm not sure that either of these people were projecting tho. The second time (with the friend in the room) i tried to introduce myself as 'x' and it came out all wrong.

YES i would like to know how this can happen as well...since when these occurred i was completely confused and i was as clueless as the people i entered.