Should I tell him how I feel over the phone or in person?

I met this wonderful guy a little bit ago and we’ve been going on fun little dates here and there to get to know each other. We were up front with each other about our previous relationships. We both seemed to have gotten out of one around the same time a few months prior to meeting, but he is definitely more healed than me. I thought I was healed and that I had moved on emotionally from the last guy, but the more I got closer to this new gentleman the more I realized I didn't like the state of my mind and heart, and we just don’t seem to have that connection.

He deserves a girl who sees a future with him, who thinks about him when he’s not around, and who gets excited when she’s with him. I don’t think I can be that girl. I’m not beating myself up over it, I just wanted to ask what you guys would suggest truthfully, if I should let him know this over the phone and end it this way, or go see him in person, and talk about it like that?