I think learning to express our emotions is very confusing, especially when we are just starting to learn how

We first have to realize the feelings are always there, whether we recognize it or not, we just haven't been focusing on them. It's like the old "don't think of pink elephants" line where you then see/have to think of pink elephants or when you decide to buy a "red car" and suddenly the streets are full of red cars.

Our brain is geared to protecting us; expressing emotions in your childhood might have gotten you in trouble? Now your T is saying you should get your frontal lobe to focus on feelings, whatever is there and you have the larger-than-life problem so all your little former annoyances with T, you see as larger and think you must "express" as anger.

"Express" though is a loaded word in itself. You could say, "Ah, I feel angry right now," in a sense of wonder, as in, isn't that interesting and exciting, I don't recall feeling that so much lately; I wonder what is going on with me that I feel this way" or you can launch into an "I'm angry at you because every time I express that I am angry at you you suggest that if I don't like you maybe I should find myself another therapist and that makes me feel like I'm being abandoned."

The "how" of the expression makes a big difference, yes?

Now, look at that second "launch". What is the bottom line? You feel like you are going to be abandoned and that scares you. That is what anger is for! To help you get to the bottom of what you feel has been taken from you and, hopefully, get it back.

There is a lot of distance between the "I feel angry" and the "why" I feel angry that has to be explored, much of it in our own head and hearts because, in the end, it is about us and our individual/particular fears.

That being true, trying to get the other person not to "trigger" our anger can't work (quit suggesting I find another therapist so I don't have to feel I'm being abandoned); instead, we have to work on a dialog with ourselves and the other person to (1) make sure our perceptions of the situation are correct (why do I think T is suggesting I find another T?) (2) to see whether I have a problem or T has actually crossed a legitimate boundary and taken something that is mine from me (is my security in danger?) and (3) to decide what action to take as a result of the conversation.

It sounds to me like you should start just expressing the name of what you feel; "I think I am annoyed/angry/really pissed right now" and stop, to open the conversation with T. Get specific (correct degree; realize that thinking about anger is going to bring up angry situations and that's a good thing as you want to learn about anger but think about the actual situation; you're sitting at T's in a therapy session, discussing anger and all the two of you are doing is talking; nothing can seriously be wrong (so far) because you are just talking, so perhaps you could skip to realizing you are afraid she is going to abandon you or annoyed and frustrated because you have seemingly been in this situation before and the pattern is repeating and you don't know what to do, or whatever; but first learn to identify what you are feeling as well as you can). T will probably say some T-classic like, "Oh? Why are you feeling angry?"

That's when you get into thoughtful/dreamy mode and start a stream of consciousness connecting dots. "Well, you just said X and that is what triggered me; I think you suggested I see another T because you don't want to see me anymore, is that correct? You start reality checking with other person, exploring what you think/feel deeper and what they think/perceive,etc. Sometimes that mini-conversation will solve whatever the problem is. What is wonderful, to me, is that focusing on exploring takes away the need for the stronger, more difficult feelings, the talking is taking action and that's the point of having feelings, to help you take effective action.

But you continue like that, exploring and going back and forth, in good faith, with the other person. Sometimes the other person IS an ***/idiot/not helpful and then you know and can fall back and regroup (decide that you want to find another T, not that the other person is abandoning you and wants you gone); you become the actor instead of allowing yourself to be acted upon.