So the more I read about your wonderful type, the more I think i'm starting to understand.
It seems to me that INFJs need some form of affirmation to "analyze" which then allows you to intuit your emotional response. However, your emotional response is entirely internal.
In other words, Emotions go in, but they don't come back out.
Now to analyze. Why do you think/feel that you are unable to express openly your true emotions? Is it because it takes you so long to process the input that by the time the output arrives there is no reason to "say/express" anything?
I get the feeling that you know exactly how you feel about something, but you are afraid or unwilling to express it. (Or don't know how?)
If you feel especially forthcoming, would you be willing to explain how the process works for you? For example " I like you a lot" comes from someone you obviously like back very much (But the person may not be aware of the degree you like them back). Explain how this data goes in and comes back out. Pretty Please =)
"It seems to me that INFJs need some form of affirmation to "analyze" which then allows you to intuit your emotional response. However, your emotional response is entirely internal.
In other words, Emotions go in, but they don't come back out. "
That is very perceptive, but your idea has some understanding black holes. I will talk just about myself, but I am an INFJ, so I think I have a right to do it. A need for affirmation to analyze that I could intuit my emotional response, is perceptive sighting, because I need open ideas (affirmation that person wants to contact with me) from other person, that I could take it into my intuition MEMORY (not a black hole), that I could sytematize the conversation which is happening at that moment. But I couldn't agree with sighting that emotions go in, but they don't come back. Conversations are happening between a few or more people, so how constructive conversation can be, it depends on the direction of feelings expressing in defined emotional trajectory. So, if people are different (in this case you have inTj and I have inFj), the emotions doesn't interacting between both sides and, logically, you can not get exact response you expect from INFJ, because you also can not give exact that what needs INFJ. So, there is no black holes, there is just different understanding (that's why not all people can be friends, I guess).
"I get the feeling that you know exactly how you feel about something, but you are afraid or unwilling to express it. (Or don't know how?)" Yes, that is also true, because in every INFJ there is different life experience (we are separate individuals, you know), so we have different understanding of ethics, and different expectations, wishes, doubts etc.
So, lets face the fact that no matter how similar definition can be of all 16 MBTI types, all we are individuals.