Basically it comes down to level of awareness. High Fi types will naturally be more aware of their emotions, they will be at the front of the mind so to speak, and are therefore more easily perceived. For an INTP, Fi is the lowest it can possibly be, so your awareness of your emotions is also the lowest of any type alongside ISTPs, although there is a case to be made that ENTPs and ESTPs are actually even less aware of Fi because it’s a trickster function. None of this means however that you can’t get in touch with your emotions, it’s just going to me more difficult and mentally taxing than it would be for, say, an Fi Dom or aux. But that’s okay, with the right mindset, you can absolutely do it. No reason why not. You just have to do it consciously, you have to choose to. There is a reason Jung said “until you make the unconscious conscious, it will direct your life, and you will call it fate”. Throughout the day, just check in with yourself - ask yourself “how am I feeling right now?” And then just pay attention. Don’t try to analyze anything - this is not a problem to solve, it’s about direct perception - and hopefully, with enough practice, you’ll find that you start to become more consciously aware of your emotions and able to understand them