The fact your paid up through two more lessons is a shame. Take a financial loss and move forward. Practice makes permanent, so any additional lessons that aren't moving towards your goals is counterproductive. I've had many students over the years come and go... it's not nearly as big a deal as you're thinking!
I agree with CJ -- Having paid up through two more lessons is a SUNK cost. Sunk costs have nothing to do with what is best to do from this point forward.