I went to add in my student loan interest, it said I met the cap of $2,500. Can someone please further explain this? I am getting a lot less this year than years past.

The student loan interest deduction is capped at a maximum of $2,500 for interest paid by law.  So, regardless, of how much interest you paid during the year on your loans, $2,500 is the maximum you will be able to deduct.  There is also a phaseout to the deduction, so when your income reaches a certain level, the amount you can deduct starts to get reduced as well.  

As for why your refund is less, we can't see your returns here and there could be many causes, but if this is your first year out of school, then you were likely used to getting an education credit on your returns before for education expenses.  Those credits can be quite substantial, especially for the first 4 years of undergrad when you can claim the American Opportunity Credit.

You can can view more information about the student loan deduction at the link below -

https://www.irs.gov/taxtopics/tc456.html