Potentially ending a project prematurely

Anyway, probably about six months ago, I agreed to write the script for someone's game. The scope was about 100k words and I'd figured I could finish it in a month or three (since I write fairly quickly), maybe 5-6 with substantial edits. I am...nowhere near finished. This is mostly because the partner is often requiring 4-5 complete rewrites per section. (Often because she's just not "feeling it" or I didn't somehow read her mind and get her characters right. Or I did, but having them behave in the way she wants them to makes them "too unlikeable" or "doesn't develop their relationships properly". Or it's all great, but it requires assets that she no longer feels like creating because it's "too much work" or she just doesn't like the design. GAH!) I've tried sharing the outline with her before I write anything (and get approval), but things still just "aren't right", often requiring major redrafting and throwing away, say, 10-20k words at a time. (Because, yep, it's hard to have a character do something rash and impulsive and hurtful but still have him be super likeable. Go...figure?) On top of that, some of her demands seem to be getting (at least to me) more unreasonable. (A recent one was that no word that was "technical" could be used - think words like "handlebar" or "pedals" for a bicycle...not words that are incredibly esoteric, just words that your average 5th grader might not know.) It's hit the point where I'm loathing working on this project. It's going to *easily* take 6 months more and, while I'm sure I can put in the 1-2 hours a day it will take, I'm feeling absolutely done. I feel bad about quitting (as I hate shoving off a responsibility). But I'm only going to get paid if the project is a success (unlikely - it's the nature of indie games), and I'm dreading work on it. (It's also taking time I could spend working on a project I enjoy and/or feel would be more likely to be a success.) Would I be an absolute jerk if I told her, "I'm done?" (I did earlier, after she'd required something like 7 revisions for a scene and was told it would stop. But clearly it hasn't and it's past the point where I find this project exhausting and demoralizing.)

Thanks for the advice. And yes, I think I'll tell her (again) that I just am not able to complete this project. (I may make up an excuse about life stuff or whatever, since I think saying, "BTW, I can't waste my life trying to read your mind" sounds mean, even if it's the truth. And I've already told her that, so...) And it's not a huge deal to me that I'm not being paid. It's a disappointment to put so much time into something just for it to not be used, but this isn't the first time and I doubt it will be the last. (Alas.)