When it happens again, would suggest a 24/7 call at that time to licensed counselors at 1-800-525-Love; http://www.klove.com is their general site.
Sleep paralysis is often a passing stage. If it's been a condition you've suffered from for some considerable time, other factors may be in play.
So, when you talk to the counselor, mention you sleep with a locked door because of trust issues.
Not crazy nor mentally disturbed, fair enough, but talking with a counselor over the phone could be worthwhile for their insight.
You might also try http://www.astraldynamics.com
"Emotions," Marilyn C. Barrack, Ph.D.
Review at http://www.amazon.com