There is absolutely no way you're an ESTJ.Posting this question somewhere more on-topic than where I'd been discussing this issue previously.
I'm an ESTJ with a lot of NFJ friends and family. I appreciate their interpersonal savvy, kindness, and creativity. They appreciate my steadiness and directness. I've heard from other NFJs that STJs appeal to them because they can take overwhelmingly detailed situations and reduce them to a sentence or two -- which calms the NFJs down immensely and helps them take action.
I acknowledge, here, that NFJs require time to Ni-Ti-dump, which I've talked with other NFJs on the forum about before. They need someone to talk at, so they can lay out all their thoughts and put everything in order. For an STJ, this seems like a prime opportunity to reduce that dumping to a brief summary and piece of advice -- which, as stated above, is one of their great strengths. They recognize this about themselves, and if they know NFJs well, they know that NFJs don't just appreciate that skill, but sometimes NEED it as well.
So, I'm having a difficult time recognizing when NFJs are using me as a sounding board without wanting my input, versus wanting someone to calm them down with Si-Te quick and reliable conclusions. In both cases, they vent at me and are stressed. In neither case will they ask me for my input. Sometimes they thank me, sometimes they are dissatisfied because they wanted me to give external validation (for their Fe), and/or just listen without presenting anything for them.
Not to mention, it's also impossible for me to distinguish that Ni-Ti-dump process, which is normal and natural, with a Ni-Ti loop, which is unhealthy. This is because if I were ever to dump information on someone similarly, it would NOT be healthy or normal, and I would need someone to snap me out of it -- because I don't use Ni or Ti and therefore don't process similarly.