1. preoccupy or fill the mind of (someone) continually, intrusively, and to a troubling extent:
Obsession is an occupation of the mind. People get obsessed with a celebrity they've never met. Are you posting images of him all over your room and intentionally trying to remind yourself of him day in and day out? No? Then you are probably not obsessed.
Love, on the other hand, is an occupation of the heart. You loved him in the past. And love is a stronger force than time, distance, pain, or even death. People wait, go to the ends of the earth, suffer, and die for those whom they love. So if the breakup was due to something other than incompatibility or foul thing, maybe reconsider! Time has been proving for you the genuineness of your love!