C2H: Maybe you place too much importance on being in a relationship. Maybe your daughter also picks up on that. No one will "Complete" us if we are not complete ourselves. Yes, it is fun to have a companion but friends are also great for that.
The time will come. Mostly I find it comes when you stop worrying about it. You do not sit home feeling sorry for yourself. You are obviously getting out there and doing things with friends and with your daughters. Try to enjoy that more and not focus on anything missing from your life.
I think you've come a long way. I just think you need a little bit more work. Don't beat yourself up for what you haven't accomplished - pride yourself for what you have done!