I think "I did him wrong" followed with "I was never no, never no, never enough" means she felt like no matter what she did she could never satisfy him completely, and she feels guilty and is wondering if it's her fault. I also think that the storyline is that she sees him now engaged to a new girl ("bell of new love") and this girl might have bragged to her trying to say why she is so much better for him, but the narrator is saying she knows it's her own fault and that the other girl shouldn't harp on about it.
I think "I did him wrong" followed with "I was never no, never no, never enough" means she felt like no matter what she did she could never satisfy him completely, and she feels guilty and is wondering if it's her fault. I also think that the storyline is that she sees him now engaged to a new girl ("bell of new love") and this girl might have bragged to her trying to say why she is so much better for him, but the narrator is saying she knows it's her own fault and that the other girl shouldn't harp on about it.