maybe it is a good time to start praying, if you dont usually pray.
try to feel your aura as a shield that nothing goes through to your body.
the presence trying to harm you may not be the same one in the beginning.

and most importantly, what do you mean by *I think I have "opened up" to the spirit world*? we are always opened to it, we just dont pay attention to it for most of the times.

did you use an ouija board or some other similar tool?