I think Kon wanted to wait as long as possible too, but judging by her breaking down while driving and begging her not to die... I think the rushed feeling is wholly intended, as thoughts spilled out quicker than she could help.
Kon clearly wants to change, and this may not be the perfect moment nor the way, but i think that's a great way to represent that it's truly a "plunge" into something different for her!
This, and also there is the whole thing with the person she has fallen in love with just having announced the intent to possibly kill herself, so Kon has a quite literal deadline coming up which is forcing her to act fast if she doesn't want to lose her.
Which also happens not to be one of her strong suits, we have seen her making a lot of very rushed impulse decisions over the course of this story - every time she thought she was about to lose Ai, in fact.
I also do love that ironically, this is probably exactly what Ai needs right now. A person who is just 100% honest to her about her feelings, and is not trying to hide anything from her. And also grounded in a way that she, as a person who, literally and figuratively, keeps being on the run from things, probably hasn't been in a long time.