“Come just as you are to me
Don't need apologies
Know that you are worthy
I'll take your bad days with your good
Walk through the storm I would
I do it all because I love you
I love you”

Katy Perry – Unconditionally Lyrics on LyricsMode
She's saying don't apologize for who you are, you're perfect and good enough. I'll be with you bad days and good. Your battles are mine, all because I love you.