What is this weird rumbling? Feelings? NOOOO!

  After a heinous breakup, you learn to distance yourself from feelings. Getting hurt down to the fiber of your being is too tremendously painful to experience again. Thankfully, I've really learned to turn off my feelings towards men. I've been on quite a few dates in the past year, not getting attached to any of them. They come and go like seasons or passing fancies. My apartment has become my favorite hangout. It's a well-protected cocoon of safety.
  I've had a couple of dates with one guy, M. We have these amazing conversations about everything from philosophy to movies. He's incredibly intelligent. Granted, I've only ever dated very intelligent men. I crave great conversation. We sit and talk and then even more amazing things happen. Lately, I've found myself thinking about him a lot. Oh, no, inner me is nervous. Why is this happening? I considered not seeing him again. What if this rumbling gets stronger? Shit. I can't have this. This is weakness. Hitmen never care about their victims feelings. Then, he told me he thinks about me a lot. What? Honestly, I've put the thought of men actually having feelings out of my head, like it's an urban legend. A man caring about a woman is right up there with ghosts and guys running around with hooks for hands killing virgins. I'm used to guys telling me what they think about me on a physical level and it never gets any deeper. To a large extent, I've kept it that way. I might have thought at times that I wanted more, but I kept it at bay. Self preservation is a wondrous thing. So, why all of  a sudden  is this seeping into my thoughts? I'm nervous. But, giddy. I've reread his texts over and over. He says things that make my knees buckle. He said he thinks of me often and wants to see me more. He's said very romantic things that made me melt inside. This is dangerous territory. I could easily fall for him. I don't know what to do. I really can't have that.  The last one I fell for utterly destroyed me. I heard lyrics from Mumford & Sons today that perfectly explained how I'm feeling.
And my head told my heart
"Let love grow"
But my heart told my head
"This time no
This time no"