First, I would recommend not taking any more tests until you prep some. If you take to many tests before prepping, IMO, you will only reprodice bad habits that may become hard to break. BikePilot is much more advanced than me, so BP may expand on this.
As for your potential the answer is lawerlike. It depends. It depends on your natural ablility and your work ethic. I went from a 153 to a high practice of 177, before settling on a 173 on test day. I went into my first diagnostic knowing nothing about the test. I did not know how many sections were on in it. I was an open, empty book.
I prepped from Feb-June. I started off with about 30 hours for the first 2-3 weeks, before slowing scaling down as I imporvewd as to prevent burn out. I took at least one test per week from the end of February to June (over 5000 questions anwered).
That being said, there was a girl in my course who started with a 151 and ended with a 153. Again I do believe I had more natural abilit. MOre importantly, I know I put in the time when she did not. So take you and you desires, ablility, and will to sacrifice, and ou may find your answer