I more closely identify with Introverted Thinking (just read up on the two).
Well in the end only you know that. I do not presume to know you because I don't.
It became extremely evident to me that I was an Fi type above and beyond anything, and once I REALLY UNDERSTOOD the difference between Fi and Fe, and also saw that while I have some Te, Ti is like a totally foreign land to me, I at least was entirely certain that I was FP.
However, I think it helped me most to look at Jung. I would suggest looking into Beebe as well, Eric B made this really cool sort of map of Beebe's function order. I can give you a couple of links.
It's just at the end of the day there is absolutely no such thing as an ISTx. If you are ISTP, so be it but the dom function is the main thing, and you do not have two.
"Sentiment without action is the ruin of the soul." - Edward Abbey
Thanks to your thread the number of fancy types is increasing.
A man builds. A parasite asks 'Where is my share?'
A man creates. A parasite says, 'What will the neighbors think?'
A man invents. A parasite says, 'Watch out, or you might tread on the toes of God... '