Lyric discussion by marsbars 

Cover art for Say Something lyrics by A Great Big World

I think that the singer has fallen desperately in love with a girl, and he gave her everything. He showed her his past, feelings, etc. He's not experienced in love, hence the line "I'm still learning to love / just starting to crawl." But it isn't enough for the one he loves, there's nothing left he can do then let her go, unless she says something to him that will stop him from giving up.

My Interpretation

You nailed it! At least in that it describes me & how I relate to this song. I feel this describes perfectly what he is saying in this song.