Dude, your dreams are always about your sub-conscious fears and hopes.
Your parents would probably throw a fit if they knew what you were doing to yourself - correct?
(probably) - you started having a bad trip and your subconscious fears of what your parents would think, if they found you like this (because, subconsciously, you were panicking about the bad-trip), is what caused the nightmares.

My advice, quit the chems, dude - anything that is made-made needs to be used carefully, whereas, natural stuff (weed) is easier and 'safer'.

That said, I would also advise anyone who is going to trip, to do it with real (that's REAL) friends - unless you have done the trip before and are aware of all the effects.
Safety first, init!

Okies, lecture over lol