Ok, let's back up a bit. You might want to research Paraffin combustion in a hybrid. You need to know what is going on. IMHO you are trying to go too far just yet without knowing enough about what is going on. It would be good for you to pick up a book on the subject and get familiar with it. I don't know if it is still available, but something like this
https://aeroconsystems.com/cart/literature-software/hybrid-design-factors-by-bill-colburn/ is a good starting point.
The statement that prompted my response is "to speed up the regression rate".
Why do you want to speed up the regression rate with Paraffin? To put it more generally, what are the advantages and issues with using Paraffin as the fuel in a hybrid rocket motor? You need to be able to answer that question offhand.
Secondly, you need to be able to design your hybrid given the expected regression rate of your chosen fuel. The physical design of the motor depends on the planned regression rate, the planned O:F ratio, Expected oxidizer mass, etc. If it isn't obvious to you how these things interrelate, and dictate major factors in your combustion chamber design, and how things like injector area vs nozzle throat area interrelate, then you aren't ready to design a hybrid. Way too high a percentage of what you might just sketch up that looks ok really isn't. It is touchier to design in some ways than solid propellant motors, and you don't have that experience either.
PERHAPS you could design a working hybrid using one of the hybrid design tools, without knowing these things. But you could design a much better one if you knew more about what was going on.
You could copy an existing design - and that includes the fuel type - and make a working hybrid. But then you wouldn't really know why it worked. You'd have a motor, but would have learned much less than you could have learned.
I highly enourage you! But the journey isn't instant. If you want it pretty quick and want it to work, purchase one or copy one. If you want to design your own, take some time out to learn more before making any design decisions. You aren't ready. Then don't set a deadline just yet. When the design is ready, it is ready.
Go Fever blows up hardware. Unless you have the hardware budget of a certain rocket company you probably can't afford to learn your lessons burning through hardware tests! The 500 I think you said you've sunk into it so far is a small part of the total by the time you are done.
Not a great picture, but 75mm static test. THRP-1 (Tiny Hybrid Rocket Project 1).
Gerald