Hmm.
Sounds like you were put under pressure - and succumbed to temptation. It's not terribly surprising, though. While I fully understand the notion of "being PIC", it's easier said than done at the moment when you are told "just do it" and the big flashing neon sign of "PPL certificate" comes in front of your eyes. It's easy in hindsight, but be honest: with all of Monday's frustrations, did you not get excited when the opportunity presented itself to just "get it done with" there and then? I know I would have been.
In pilot lingo, it's a bit like getting behind the plane.
It also sounds like there is frustration on both sides. Your CFI seems to realize that something's wrong - after all, if I understand correctly, you have over 150 hours of training time, which should be plenty sufficient for attaining your certificate - but on the other hand, he doesn't seem to be accountable to his part of it and tell you "hey, this isn't working out, let me help you find someone who can get you over this hump". Yes, you should be initiating that conversation yourself, but it's a hard one to have. I DO know that from experience; I had to fire my first instructor, and it took me two months longer than it should have because he was a really nice guy and I liked him a lot. So it was easy to tell myself, at that point in my training, that it was just a mindset and attitude problem on my part and that I could fix it if I bit down hard. Shoot, with the level of intimacy (drop the stupid jokes right there, you know what I mean) one develops with one's instructor, firing them is like a breakup conversation. No one likes those, do they?
Well, it wasn't. The real problem was the one I knew all along - he was great to get me through the first portion (teaching me how to fly), but once we got to a certain point and I had to refine my skills, our communications failed miserably and I stopped learning effectively. This became evident when I was running with two instructors concurrently for a couple weeks and with the new one, started advancing rapidly again, yet with the old one, I couldn't even execute a proper S-turn.
The one truly concerning statement in your story has been pointed out repeatedly. If your CFI truly does not think you're safe to fly, yet is signing you off for the checkride hoping you'll get lucky, he should lose his CFI license, and the sooner the better. Is this really what he said? this is not about blame, Sarah. You need to look inside yourself and honestly answer the question "am I safe to fly?". Really be honest. If you can't answer that confidently, with no reservation, then you shouldn't want to get the license. And if you can, then you need someone new to work with you, NOW.