Lyric discussion by Siyeed 

Cover art for Let Live lyrics by Of Mice & Men

As far as I can tell he loves a girl but she fucked him over and he knows she's ruining his life but he can't let her go.

You are actually close I believe. As far as I can tell this is about Austin and his wife separating, he loves her still even tho she fucked him over and left while she was pregnant with his child.

My Interpretation