hmmmmmmm..... It seems to me that what might help is that you work on changing what you value within yourself. There are many many people out there that can't have children for various reasons and they most likely have had to change their way of thinking if they felt pro-creating was such a huge value.
I hope I'm not sounding callous or cold-- it's not my intention.
It can be helpful for some that have made certain choices-- like you have (having your tubes tied) to come to terms with those choices(if you don't feel parenting is an option) and find new values that give your life a lift.
I have a sister that could never get pregnant, a niece(from a different sister- of course, I had 5 sisters, now I have 4)) that is developmentally unable to care for a child and so she has had the operation like you did. They both would love to have a child-- however, they have had to come to terms with their reality. My niece helps every Sunday at her church with the Sunday School and the kids just LOVE her. My sister has become a type of "auntie" to her friends' children and they lover her and they will always have a special bond-- yet she doesn't have the responsibilty of a child- 24/7. (she struggles with staying clean from alcohol-- but part time mothering works great for her.)
I think it's an issue of accepting what you feel is your reality. Maybe you swore you wouldn't have kids so they woudln't go through what you went through...... maybe not having a role-model of proper mothering, you feel it's best to not try and take that huge job on(and understandably, it's the hardest job in the world-IMO) Whatever the various reasons-- it would be beneficial to realize those reasons and try to come to peace with it.
I'm sorry this is so difficult for you. I hope I've not offended, I was hoping to help you feel better about things.

don't know if I was understood that way though-- I do hope so.......
DePressedMe--
mandy