How do I let a guy down?

So, I’m a freshman in college and have been talking to this guy for a few months now. At first I really did like him. We were spending all of our time together and I really did like him. I guess over time I’m just losing interest. One he doesn’t want to put a label on anything and I do so if you don’t want to do that I’m going to mode one. Two, he’s graduating this year and I’m just starting. I just feel like we’re going two completely opposite directions in our lives and it’s not going to work out in the end. But, how do I let him know how I’m feeling without hurting his feelings to much?