I'm guessing this is for the SAE heavy lift contest? My club in Fort Worth hosts it every other year.
Where are you calculating the load to be? If you are doing the math as if the load is on the wingtip, your numbers are going to be way over. But wing loading is distributed along the wing's length, not evenly exactly, but fairly close. You can probably get close enough by calculating the stress in the middle of the wing half, but that may not be accurate enough for your professor.
Here's a paper on the topic written by the Aggies. Aside from that hideous maroon and white color scheme they always do, they've showed up with some decent planes over the years. To my knowledge, they've at least never folded a wing.
atmeh_paper.pdf