This fear of commitment that I have

I recently got into a relationship, we've been together for a month now... And I love her, she's the best girlfriend I've ever had. Ive never felt this way about anyone until I met her... But recently, when we were talking, she got upset because she realized I had a fear of commitment... I havent been in enough relationships to know that I have that fear. When she said that I was confused and when I learned what it was... It's been bothering me the whole time. I have this fear of commitment that I never knew I had. And we almost broke up... But I told her I was willing to fix this, because I want to change, I dont want to have this fear... I dont really know what to do...