Yeah I would agree with BCAA. If you have not figured out why podiatry then this is not a field for you. Even if MD/DO/DDS etc were your orginal plan and DPM is plan B you still have think of why DPM is a good alternative.
You do not have to write it overnight. Collect ideas, put them into an outline, then start to connect the dots more and more, and eventually you will have a coherent essay.
By the way when you do get in you are going have to do this all over again pretty much with residency, so it is probably a skill worth learning.