Profoundhappiness:
I honestly don't know what caused it in my childhood, though I am sure my best friend at the time played a big part in it. We met when we were around 6 years old and we are still friends to this day, though I have definitely shut down opening my soul to hers because hers is just so... hopeful and sad and angry and loving and everything all at once. My amazing best friend that I've had now for 8 years was probably the one that saved me from becoming a terrible person. Anyway, from the beginning I considered her my BEST FRIEND, a friend that I would spend the rest of my life with and share my deepest thoughts with. But the more I opened myself up, the more I became exactly like her. This mean person that was constantly negative and hating of life (which I am not AT ALL, but back then I didn't realize that). One moment I remember really specifically is when we were in my basement and for some reason I just said "I don't believe in God, I don't think I ever have. What do you think?" And out of all the answers she could give me, she told me that I was weird, wrong, going to hell, etc. Now that's an extreme. She constantly put me down for everything, even minor things like telling me my bangs looked like shit. And as I've been thinking about this over the years and talking with my ENFJ best friend, chameleonism to me just seems like it really stems from having such creative, weird, odd, insightful thoughts that when you are younger you feel free to tell to everyone, until they criticize you and make you feel like you're strange, and then you do start feeling strange because you feel what they feel. You feel their confusion, their inability to understand, or when they don't even try to understand. So as you grow up, you keep those "weird" thoughts in your head because you were told from the start that they're wrong, so you believe that by adopting others' emotions, you can create this sort of identity for yourself that uniquely caters to them. On the outside you are them, but on the inside, the mind and imagination can become astoundingly real and amazing, maybe because by not offering our truest thoughts, we don't have the criticism from others, so we can continue to think our craziest thoughts. But this can also backfire, because while the imagination can be a good thing in your youth, seeing the terrible things we see while growing up can lead our imaginations to the scariest of places, which is perhaps why we don't share ourselves with others. We know what we have inside, we don't want others to feel our pain.
As for that bad friend of mine, and I know this is really an INFJ thing, is that I can never let her go. Never end our friendship. Why?, even though she put me through this and made me feel bad at times for being me, I still love her. I still know her soul. I know who she was, who she could've become, who she can become, and honestly it just KILLS ME that even when I gave her my soul, she couldn't and wouldn't accept it. It hurts more than anything in the entire world. I know she knows that I gave it to her, and I think that's why she still comes back to me today, texting and calling much more often than I would to her. It's also just amazing though to hangout with someone you gave your soul to, to know that they saw the real you and didn't like it, or didn't understand it. It makes chameleonism nonexistent. Why hide from someone that you already know disapproves of you, but at the same time loves you in her own way. And that love that I see in her, that potential for a beautiful person, that is why I keep coming back. I think I really got off topic there, but while my stress came from one main person, you had many. It most likely manifested itself in the same way that mine did.
As for being a comfortable and confident person, I completely lost those around that girl. In order to get it back: understanding, love and the realization that other peoples troubles shouldn't make ME feel like shit. There are so many sad and terrible things in this world, but when I feel love for someone it is almost impossible to describe. It's like my whole being is filled with utter joy and fullness. And I realized that its so much harder to love than to hate, to see the differences. The confidence will return when emotions fill the soul, when I look at and feel people both negative and positive. Something I've also been trying lately is focus my mind more on the external world and people and how we're all the same and that even though someone did/does mean things to me, I understand. I get where they're coming from. It is hard as hell, especially around lots of people. Just... project your mind outward, love outward instead of keeping it inside. Yeah, people will see more of the real you, and you will know that they do, but you will also know that if you do become friends with them, they'll accept that inner world. Truly amazing, but it takes a lot of focus on the external world, which is exhausting.
I know exactly what you mean when you say you started to feel. Like I said above, more focus on the external world and our underdeveloped Se helped balance that introverted intuition. As that develops, so do such intense feelings. I can cry in the blink of an eye, be filled with pure joy, pure hatred, contempt, etc. And it's so weird to finally say to yourself, "hey, I was right all along, even though all these years people made me sound like the crazy one." A great realization right there.
And as to stop hearing the negativity and being reminded of all its terrible feelings everyday, I've just gone the route of yes, you can think that, but I know it's not true because that's who I am and I love myself. Anyways, any person who feels the need to harass you like that, they don't deserve your soul.
It's a lot. This is just how I've been doing things for a little while, though I know I still have a long way to go. There are so many methods out there for INFJs to learn how to stay true to themselves, so if you try out a lot, or one you think would work with you, you will be good to go. Just don't follow what I say, because everyone is so goddamn different i this world it still astounds me to this day. So many people, so many energies, personalities, likes, dislikes, activities, etc. Blows my gosh darn mind.