(I'm new: will probably do an intro post as well, but thought this topic is interesting, so wanted to chime in, if that's okay.)
I don't think the way I express Fe is fake, but I do think I use Fe methods of expression to dissemble and abridge how I actually am experiencing the world at any particular moment. I don't think this is inauthentic, because my most authentic self is represented by the impressions, images/sounds, and viewpoints I experience internally through Ni, which are colored by feeling, but by colored I really do mean something like color, or a non-representational subjective state. I can't honestly and without censoring express myself without it sounding like tripped-out free verse or a treatise on metaphysics, either of which, if I say it out loud, become automatically categorized as a certain kind of Fe thing (oh, I'm being poetical! Oh, I'm being philosophical/pedantic!) and lose the immediacy of the raw interior experience. I don't know if most INFJs experience their inner worlds in this way (though I've met several INFJ and INTJ IRL who describe something similar), but because there is something fundamentally untranslatable about my feelings and perceptions, I don't think it's problematic to come up with a socially intelligible way of expressing part of what I mean. I actually enjoy it.
For example, I think it's really neat when I can come up with a very simple way of expressing a complex thought I'm having to someone who doesn't "get it," or gloss a powerful feeling into a more universal expression of human experience, something relatable. Fe isn't about hiding or revealing a feeling so much as how you do it: there's a difference between ranting and sobbing about the inherent villainy of mankind and stating clearly that you're frustrated by a person who can't hear what you're saying, when it seems appropriate, giving your conversation partner an opportunity to weigh in on frustrating people - positive or negative - and then going off of that or getting out of the conversation if the other person doesn't see where you're coming from. It's a delicate give and take in conversation and relationship that can be quite interesting from a more introverted point of view instead of bothersome, something you have to do without recourse to your Ni. Fe doesn't have to be an out-of-mind or out-of-self experience, which I think, when an INFJ experiences too much dissonance between inner and outer worlds, can become tantamount to an out-of-body experience, which is super upsetting.
I also think that Fe, using other extraverted functions too (like Se), can be quite creative, not just regulatory. For example, as to trippy Ni stuff, I can, instead of sounding like a stoner prophet, actually write a poem or bust out the watercolors. This might be more a Ti or Se thing (the poem or the painting) in execution, but it does have a major Fe component to it, namely that I am channeling my energy into a symbolic expression that has an established social significance. A poem that captures some odd angle on a vase of flowers or personifies said vase unconventionally or something is, despite the obscurity of the language or the imagery, completely accessible in a conventional sense because it codes as a poem, and the originator as a poet, a known social quantity. Doing so defangs what could otherwise be a revolutionary rupture in social norms, but people probably will not think you're, I don't know, schizophrenic or something for writing or reading/enjoying said poem. Which can make things easier.
I guess what I mean is that despite the fact that I do use Fe to make nice, and can slip into pretty conventional behaviors and emotionalism without thinking, I've become a lot more comfortable with my Fe since I realized that it can still be guided by and in fact enhance my experience of Ni, which makes me feel less torn and fake and misunderstood. Fe is my ambassador, and knows my ways: it is therefore an honest representation of myself even if it isn't speaking my native tongue when abroad.