Ugh, I'm literally 50-50 J/P so it feels like no matter what I'm doing I'm fighting myself. What I usually end up doing is imagining a lot of different ways that any given event or moment could go, and then in that second do absolutely none of them and pick something else. If I don't have a generalized plan, I get stressed, but then if I follow the plan, I get bored.
I feel guilty when I'm late but it's hard for me not to be, I have poor completion-per-idea so I just think of like a billion ideas and hold onto them forever (thus completing a lot of projects by most people's standards but a tiny fraction of my Good Ideas), I'm wishy-washy but very good at precisely detailing the conditions of my wishy-washiness, and I'm ambitious as hell but terrible at thinking ahead or doing anything long-term.
All sounds really familiar to me, minus the frustration.
I have a billion ideas, too, but I'm generally content with treasuring the ideas themselves and only completing or half-completing something once in a while. I'm ambitious as hell, but intimidate myself with my more ambitious ideas and never come up with long-term strategies for pursuing them. But I get a ton of satisfaction out of it when I do little things that feel like progress. Doesn't bother me when I'm late. Only bothers me that people are so uptight about it. Unless I'm
late to the point of causing real problems, and then I feel bad.
Being IN*P carries plenty of its own problems, though... like feeling generally incompatible with the world most of the time. Or being seen as weak or incompetent because I analyze and ethically judge my own actions more strictly and honestly than others. I could wrap a verbal fist around the ego-hearts of most people I know, but I never will because it's just not in my nature.