Fi Dominant

Well, the customary MBTI answer is just to develop extraverted intuition. Learn to be more outside of yourself, see new possibilities and be more objective about what is going on.
My most basic advice here is to get out of your head. When someone says something to you, your natural tendency is to pay attention to how that comment feels to you and then act on it. I want you to pay a lot more attention to other possibilities about meaning and intent than just how you immediately receive it. If somebody says, "you have a problem," it could of course mean that you are being criticised, but maybe the other person is just trying to help by making you aware of what is going on, he might be compassionate.
Remember that INFJs are directing in their language (Stop that loud music) while INFPs are more indirect (the music is quite loud), but that there is essentially no difference in the meaning of what is being said. To an Fi-dom it will, however, feel as a personal blow very easily if they don't develop a more objective way of seeing the world.

Fi in and of itself doesn't have to be an emotional prison sentence. Actually, Fi is just as impersonal and devoid of emotion as any other function. It basically takes in information and compares it to predetermined values, beliefs, principles, etc. and sorts it in an exceedingly impersonal fashion into categories of good and bad (that's an elementary summation, but you get the idea.) That's why you can highly value love and being nonjudgmental, but find yourself being judgmental of people you love if they say or do something that doesn't align with your established values, because Fi doesn't take into account your feelings when it's doing its thing. It's just a robot sorting machine, really. What happens is when something gets put into the "bad" pile, you then react to it emotionally because "bad" conjures up bad feelings.

As @UnicornRainbowLove said, developing your auxiliary extroverted function will add a second layer to this automatic sorting process that Fi undergoes. But if perceiving functions are subconscious and we're not generally aware of them, how do you do that? As the examples given, you have consciously look for alternate possibilities for Fi to consider. By purposefully seeking out alternatives, Ne will liven up and start feeding you alternatives.

As you can see from the two examples, only viewing things from the subjective, introverted POV dead ends with a reaction. Adding an extroverted POV opens up more possibilities. (I could have delineated in more detail on Prong 2, but I only have an hour left to take a nap before work, heh heh)

Another thing to keep in mind, and something that was discussed on a previous thread, emotion really is felt as a physical sensation in the body. Personally, I can't control this sensation anymore than I can control my heart beating. It's best to wait for those sensations to subside before reacting to things. It's damn hard to objectively consider other, more reasonable explanations in the present moment when your mind is clouded with emotion, and rather unproductive. I would think your INFJ boyfriend would understand your reasoning if you explained that you have no control when these emotions invade your body and a conversation would be more productive in a few minutes (at least I would hope so....)

PS: Pardon my Te intrusion with the Excel flowcharts. Don't know what came over me!!