First of all we can't diagnose anybody, that's not our realm and we don't have the credentials to do so. When you meditate you are raising energy, so if there's something there, whatever it may be will be drawn to this energy. Do you do cast a circle before mediating? That may help you feel more comfortable before going into a mediative state. As far as a pentagram is concerned, if you feel drawn to use one, then use one. There's also many gems or stones that will help with protection. It's really a matter of preference I believe. But before you do anything with a pentagram or any type of stone for protection, I would cleanse it first.

Also are there any antiques in your home?

There's a few things going through my mind right now with this so, just bare with me for a second.

Kalf, you said this started when you were around 13 correct? And then disappeared and started back up when you were 17? I'm wondering and without getting too personal, if you have been terribly distraught over a long period of time. Sometimes people who are sensitive to spirits and things around them, can cause manifestations themselves. Especially if there's more going on recently with how you are feeling or something very difficult you are going through yourself. These manifestations can happen. And this doesn't happen just the nights you meditate correct?

Also, another idea I had was that possibly this is your spirit guide that is trying to get your attention and let you know it's there for you.

I would highly recommend journaling every day and see if that doesn't help. At least that way, if you are feeling down or distraught, by putting things in your journal, you're clearing the air sort of speak and getting out your frustration or anger in that way. Give it a awhile and see what happens.

Personally, if it was me, I would stop with the Occult stuff and mediating until you know for sure what is going on. Because like I said in my first response, you are raising more energy every time you meditate. I think it would be wise to get a handle on what's happening here before possibly adding to it with getting into the occult. But to answer your question about cleansing a talisman, I would recommend leaving it out under the full moon and ask which ever deity you believe in to cleanse it and make it pure. Just be sure that you are drawn to that talisman and feel some kind connection to it. Don't go just buy something, if it doesn't resonate with you.

Interesting that you should say these events became more frequent at the age of 13 and tailed off when you reached 17.

Pubescent teenagers are extremely 'adept' at picking up on the energies surrounding them and, unfortunately,  they seem to lose this 'ability' as they get older.

These experiences have stayed with you however, and maybe, doing recent research on them, has once again opened up a receptive channel within you.

This isn't a bad thing in my opinion...on the contrary.  I often feel something touching me, or hear whispers and sounds in my ear.  They don't bother me, I'm quite used to them now.  When you were diagnosed with 'extreme paranoia' were you given any medication for it? Or was it a case of 'pull yourself together, now off you go?'  If you are overly concerned, I would advise you to go see your doctor again.

I think meditating is a good idea [you don't have to cast a circle before you meditate by the way].  The answers to many questions come to us during meditation, and I think it will help you along your path to understanding your spirituality, and help you reach an inner calmness.

As regards to the question of an amulet, chose something that you think would benefit you, something that you personally feel drawn to.