I don't have much time to write. I haven't been here in a while, a couple years and I'm happy to see INTPs keeping on. I wanted to quickly get this message out here and I hope that it finds the right eyes
I don't have time to go through theory but you don't have to doubt my accuracy. Se is what you want to develop, "extroverted sensing", what we should just call action. Emotional maturity will come to you with age and experience – if you don't get stuck, if you keep getting up and keep moving forward. You'll find that to keep moving forward you'll need to forgive yourself for your emotional transgressions because they won't be developed well into your 50's basically. You will hurt a lot of people, you will hurt yourself the most. It's just the way your mind functions and develops and you can minimize the damage if you do try, for brevity
For an INTP to be balanced they need to take a lot of action, to you it will feel like a lot of action but in reality or subjectively, in comparison to many other types, you're not really going that fast at all, you're not doing much. You're "doing" a lot in your head. Because our minds are overactive, we need to balance the thought with action. We get stuck in our heads and human minds are complex. The main challenge with the mind is ego and identity. In the ego you will encounter complexities, often with duals; fear, confidence, arrogance, doubt, anxiety, pride .. an endless list and often what happens is your "awareness", your "you/self" gets sucked into your head and you identify with it. You will basically think that you're your thoughts. When you have good thoughts you'll think that's who you are, when you have bad thoughts you'll think that's who you are. You'll be your mind and you're not, you're a lot more
Gym, yoga, stretching, sport, meditation. These will build presence/awareness in your body, consciousness, "you" in your body and from this you can, in a sense unite the mind and body. When you can feel your body you can feel your emotions clearer and you can navigate them even better, if you're willing to feel them obviously.
Dear INTP, if you ever get stuck in your life, do something. Clean your room, go for a run, talk to someone, punch a punching bag, sing, dance, write, draw. Build momentum, finish doing something. Explore (Ne) something Physically (Se). Your thoughts (Ti) will engage automatically, it's not something you need to DO, it's just the way your mind functions. Pretty basic message but practice it, do it. When you're stuck, you're stuck mentally. Pick yourself up, literally, you physically pick yourself up; for example from your bed, is like the metaphor, the practical wisdom.