Do you listen to your heart or head?

My husband and I have been married almost 3 years, the last 7 months we have been separated. We married very young (20) and very fast (5 months of dating). He is a nice man and treats me well. I left for many reasons, mainly because I wasn't happy. I just felt like I wasn't able to be myself and I was being held back. I felt like I made the wrong decision. He loves me so much and would do anything for me. He wants us to work things out. I have agreed to try and work on things. Things are ok. We don't fight, never really did. But things are just ok. My head is saying to stay with him because I know he will never hurt me and I will always have a loyal companion and will always be taken care of and loved but could miss out on THE ONE. My heart is saying to leave him because there is someone out there that will make me TRULY happy but then I risk heartaches and never finding someone that loves me as much as my husband. So, do I listen to my head or heart?