Do you think maybe it turned into a dream after a while?
The astral world has mostly differences to the real world. I would not call this a dream. I call a OBE a dream, if one forgets that one is not in the real world and start to act like in a dream. Otherwise it remains a OBE, even if all changes.
So I hopped back into my body, and shouted lets remember this! Well I jump in... and start to cough up this nasty stuff and it hurt... It wasn't pleasant... :/ Did I jump into the wrong body?
You dont need to go into a body. You will go back automatically or if you just say "stop" or close your eyes, till you are awake (takes maybe several seconds, but works).
Why did it hurt so bad jumping into my or this other guys body (by mistake) I looked to see if it was me who coughed it up and it wasn't... I was perfectly fine.
Maybe was none of them yours. In many OBEs are faked bodys visible. On wrong places, in wrong positions, or wrong amounts. In other OBEs is no physical body or just fog visible. One can never be shure to jump in the physical body. In many OBEs does the physical body or its position, have even no effect.