Depends what you want to do.
I don't think you should change schools, because you are in an ivy league school, and what is waiting outside of an ivy league school? there might be a community you would better fit in, but then again you don't want to get carried away in the party scene of a large school (or maybe you do, that is fine)
However, explore different classes that you might like. I for myself, am mostly undecided in my major, but I right now I hope to get an MD when I get out of undergraduate school. Don't be tunnel visioned, keep your options open, be open to different things and classes. At my school, they say its normal to change your major 4-5 times during your time at the university. Explore some classes like Hebrew, engineering classes, history of music, Greek mythology.... anything that sounds interesting. One class I decided to take this term was History 195: Witches, Alchemy, & the Golem, which was a really interesting writing course which we studied about the roots of each of the myths. Explore, and be optimistic. You will find something you never knew you liked.
I felt similar to the way you feel now. I felt filled with a certain melancholy. I began to believe that things at the University were not what I originally thought they would be. I was disillusioned like you were, but one day, I remembered how psyched I was to go to the university of my dreams, how I could make so many new friends, and get a feel for college life. Remember your aspirations that you had prior to college, and rekindle the fire of possibilities. Don't give up on your pre-college ideas of success and happiness.