INFJ dealing with his darkness

Maybe the title is too poethic for what I'll asking to you: Am I the only one who feels himself not to be completely authentic or good?

Yes, INFJ people synch with people emotion using strong Fe. They feel what other feels on their skin with a lot of empaty etc. You already know all the INFJ stuff. But I think sometimes INFJ have also a strange rage. Is a deep emotion, not a common "rage".

I saw the same trait in some INFJ villain. It is as if it was a behavior bordering on wickedness, made of conviction. Conviction of one's inner world. So: why I can't feel to be a good/autenthic person?

I help others. I sunstain others. I'm a really good friend and partner. But if I watch into myself, I see a world made of darkness. Strange and crazy thoughts, whom make me feel incomplete, but also on another plane of existance. I feel I'm not living the right world, but my life is not bad. I'm happy of my life. But ther's always this thing inside me I can't deal with, and it's hard for me to explain it.

I think it is caused by Ni. That deep web of consciousness that works in continuum.

Now, obviously I don't know if it is something that many INFJ feel. It probably only applies to individual cases. But I still don't feel authentic. Even when I'm extremely good to others. I have known very few INFJ people in life. One of them was terrified of the idea of ​​having a "dark" side. She was convinced that she had not the slightest trace of it. I thought she said it because she fears it, and it is maybe the same fear that I have, but I would like to deal with, not to flee.

I don't like to write post because I'm very shy, but I can't live without speaking to someone about it.

Is it common to other INFJ out there?

EDIT: I wasn't expecting so many answers. Thank you all! I need more time to answer to you all =)