Indie songs about not being good enough for a girl I once loved?

I gave up on the best relationship of my life prematurely, and I want to give her a parting "apology" CD mix. Songs along the lines of Warren Zevon "She's too good for me," Colin Hay "I just don't think I'll ever get over you," Jackson Browne "These Days." This girl won my heart with the CD's she used to create for me and deserves a fitting apology from me along the same lines. Thanks!