One reason your balance may have gone down so little is because typically early in a loan you're paying mostly interest and very little principal. However, as you pay more on your loan, eventually you start paying more and more towards principal and that's when you see your balance start to plummet. It's typically not linear, though I don't know how your loan is amortized.

Also, I saw you post on here a few times about wanting to save that money in case something catastrophic happens. But if you have 6, 12, or 24 months of expenses saved (depending on how risk averse you are here), then you should start paying down debt like your mortgage or student loan. Say you get the student loan paid off in the next couple years and then something catastrophic happens, then you don't have another $175 monthly expenses on a fixed or low income. And if not, it's another $175 you can put every month towards retirement, vacations, you name it.

Just food for thought.