Lindsey,
This is a tough call.
If you decide to wait for the new exam, you will deal with the ambiguity about the new format, courses will need to be renewed, it would take some time. Study time, I'm pretty sure, will remain the same, it's not a shortcut to wait for a new exam.
On the other hand, there is a well-aged current exam with tons of collected experiences on how to prepare for it, which scores one should be hitting on practice exams, etc. You've been studying for 1-1.5 months now, it might be not enough to prepare well for the exam. Getting 60% after 1 month of preparation is normal. It's important how you strategize your preparations, whether you have a clear plan on how you prepare, and how you work with the practice results. For me, practice tests/exams were a good indicator where I lacked knowledge. If you consistently work on the areas where you lack understanding/knowledge, you should see in the results that you at least get better in % for these areas. Btw, when you mention practice questions, do you mean just quizzes, or practice exams? Once you have familiarised yourself with all the areas of PMBOK, I encourage you to start taking practice 4-hrs exams. It will give you a holistic, 360-degree view, of your knowledge.
To have confidence when taking an exam, it's best to target consistently getting at least 75% or more on practice exams, whatever you would choose: the current or the new exam.