Heartbreakophobic
A person who is so afraid of getting hurt by their partner that they try not to fall in love and reject anyone who tries to build a serious relationship towards them.
"Charlie broke up with Denise when she told him that she loved him, although they've been together for a year!"
"Oh yeah, that guy is such a heartbreakophobic!"
"Oh yeah, that guy is such a heartbreakophobic!"