Results published by others first in parallel. Is my work still publishable? I am a college student who worked on a small problem in applied mathematics for two years. I recently get together some results that could be sent to publish. However when I am finishing  my draft I find a work published in a decent journal six days ago solving almost the same problem.

What can I do? The math problem is very specific so I cannot change the problem a little bit to make my work unique.

Explanation for the "almost": The abstraction/essence of the problem is exactly the same. However, since this applied math problem has been applied to many fields of science, our story and approach are completely different. I said "almost" because the core problem is the same. However, the main problem is associated with some peripheral problems that are not that important. We have done different extensions.
Get personalized advice from a professor at your college. It sounds like your current problem is not publishable anymore since you've been preempted. Still, there could be a way to spin it so that it's still publishable (the fact that you're using it in a different field is a good sign), and if so a professor at your college who can examine the problem and the proof firsthand is the best-positioned person to help.