I don't think it has anything do do with time. it's been there our whole lives.
Whatever it is, it's clear that our spouses didn't cause it.
Try reading I'm Okay, You're Okay. The first chapter is psycho-bable, but the rest is eye-opening. It talks about that core hurt.
To fill holes I find it helps to volunteer to help people that are less fortunate than me and focusing on how grateful I am for what I have.
Me 45, H 46, S 23, M 26, Together 30, Bomb 6-2-08, S 6-19-08; H left 12-29-08. H home 12-09, Still MLC in 2012! Me- I have my big girl panties on. Bring it.