God's grace IS enough, but am I lacking faith in His grace or am I just too prideful to accept His grace?

The other day during worship, we sang a song called Your Grace is Enough by Matt Maher. Vivacious, upbeat, and lively, I fell in love with this feel-good song the very first time I heard it just because of the simple and catchy melody line with a driving beat that makes it energetic. I loved the straightforward guitar riffs. The more I listened to it, the more I loved it and the more it got stuck in my head. The more I listened, the more i appreciated the lyrics of the song thereby making me like it more and listen to it more. Simply put, I just really like the song. Something strange happened on Sunday during service though. Something didn't feel quite right when the congregation was singing it....when I was singing it. It might have been partially due to the weird combination in the worship team (?). If I remember correctly, I believe there were no drums in this particular song so it sounded hollow but that is besides the point. When the song started, I started singing, but I just couldn't get myself into the song. Strange, because as I mentioned above, I love this song. I felt like something was holding me back form singing and proclaiming that God's Grace is enough for me. I couldn't get into the song so I just started reading the lyrics and began to ponder. "Your Grace is enough, Your Grace is enough, Your Grace is enough for me." How could I not be into this song?! How is God's grace not enough for me?! I didn't get it. I'm pretty sure I understand God's grace. I don't mean i can fully comprehend every detail of His Grace, but I do understand the premise of it. Was I lacking faith in trusting that God's grace is enough for me? Possibly? Or was I too prideful to accept God's grace in thinking that I should somehow pay God for His grace? I don't know. I was confused and I'm still sort of confused...

Pour down your mercy and grace on me oh Lord. Reveal yourself to me and help me realize that your grace has liberated me from the bondage of the world's expectations of me and of my own expectations for myself. Reveal your grace to me in ways that I can understand, and help me grasp and revel in the glory that is Your grace. Break my pride, God (gently please), so that I will learn to not lean on my own understanding but that I may look to you and follow the path that you have set before me.