Rushed

So me and this guy have been talking for about 3 weeks and he’s already head over heels for me. We’re cool and all but it has gotten to a point where I’m starting to feel really uncomfortable and weirded out. We have called about 5 times ever since we started talking and see each other about 2 times every week. He already calls me hun which makes me feel uncomfortable due to the fact that I don’t want to rush in to things and it’s super early in to the friendship. I want to express these feelings to him but I don’t know how to tell him in a nice way without him getting too hurt. How can I tell him?