How do I break up with him without hurting him?

I honestly feel like I made a mistake. I started dating a guy only a few months after me and my boyfriend broke up. I was lonely and sad and desperate at the time. He gave me a lot if attention that I was missing. My ex was abusive and I still feel hurt over it. He would always tell me I was ugly, or fat, he was also possesive and controlling. My new bf is a nice guy and I do not want to hurt him. I feel sorry for him because he has been abused his whole life and has some serious depression from it. He told me that he is so glad I have come into his life which makes me feel worse. Now I feel scared to break up with him. I do like him but I am starting to feel uncomfortable. I feel uncomfortable saying “I love you”. I dont feel right about this situation. I am scared of commitment. I am scared of relationships. I feel overwhelmed. I need a break from all of this.