Until genetic research produces the faultless human (which I hope it never does, except for certain physical attributes
) everyone has a range of problems to overcome when they learn new skills. The facts are that a lot of people are poor at doing sums on the ground, that wherever we start on the numerical scale we all get worse in the air, and that in flying there are certain numerical answers that need to be correct and others that only need to be guesstimates. How is it then that average imperfect mortals can learn to fly safely? - it's because there are many different ways to approach learning/teaching and the FI's job (with the stude) is to find the tools and ways to work which suit the individual.
In your case it may take longer than someone who enjoys doing mathematical gymnastics, but equally they may struggle on something which you race through. Choose an experienced FI and try to get them to teach you graphical methods wherever possible.
HFD