that "pendant" you are talking about, is it the Saint Benedict medal? whether it is or not, the Saint Benedict medal does the same as what you described, and you can get them very easily.
put "Saint Benedict" in the search on this site -
www.leafletonline.com
they have medals, crosses, books, and more.
i think it would be very helpful for you to contact a priest about this, even if you find it hard to trust them, they really can't do anything to you if they don't believe you, although i do have a suggestion, the priests from the fssp take things like this very seriously, and if you have one near you, i'm sure they would come to help you, or if you don't have one near you, then i'd still recommend calling one of them, because they will still help you however they can -
http://www.fssp.org/en/coordonnees.htmjust see if there's one near you, or pick one you think sounds good and call them.
i would also suggest getting a spiritual director to help you with your religion and spiritual life, which is something you can also do on the phone, like if you find that you like one of those priests from the fssp, they would make great spiritual directors.
do you have holy water, blessed salt, and blessed oil? those are very powerful things to make the devil run away,
also seek help from the Blessed Mother, say the rosary every day, and pray the Hail Mary when you feel scared or upset,
the saint Michael is a very good prayer to, as you already know, and another thing to do is simply say "Jesus" or "Jesus help me", His name alone is enough to send demons flying.
i know these things are scary, i've had experiences of my own with the devil, but you have to be courageous, remember that Jesus is always with you, and you have a power inside of you that the devil is
terrified of, the devil really can do no real harm to you, he wants to scare you and discourage you and distract you, especially when he sees that he is losing you, he is really just a punk, and you are more powerful then he is, the only thing stopping you right now is your fear, but God can help you with that to if you just ask.
another powerful weapon against the devil is fasting and mortification, which are things that you should talk to your priest about, because i know of alot of people who try to fast and just get it all wrong, like one person i know of, will go and not eat all day, until finally he is to hungry and just ends up gorging himself
neutral so yeah...there are guild lines to follow, but for advice on mortification, here is a nice article i have on my forum that will explain that well -
http://www.gaiaonline.com/guilds/viewtopic.php?t=13047443and regarding your spiritual life, taking part in the sacraments will be a big help, confession every month at the least, and communion when you are in the state of grace.
and also Eucharistic adoration, which will help you in your spiritual life and your relationship with God immensely.
also spiritual reading, like the lives of the saints, and the writings of the saints, or anything you find interesting on these sites -
www.tanbooks.com
www.fraternitypublications.com
i really don't know a heck of alot on possessions and exorcisms, so i definitely recommend talking to a priest about this,
alright, hope this helps, tc.