When is it time to shelve my draft?

to shelve or not to shelve?

This is more so a cry for help than a rhetorical question. I am contemplating shelving my current - and first - book draft ever.

I am completely, wonderfully, emotionally attached to this book and these characters. They were my first book idea ever. They were my first completed first draft. They allowed me to be vulnerable online and attend a writing course online. They have allowed me to challenge myself in creative ways I never have before.

However, I fear I may be outgrowing them, in a sense.