I've been following your recent threads on Relationships, dontcall. As I recall, you had a very triumphalist thread a couple months ago about how you were resolved to quit dating, focus on yourself, and stating that you were happy with yourself as you are for the first time in forever. And you have been yo-yo'ing since: dissatisfied with evenings in on your own, and in the end still feeling as needy and as unworthy as when you were in relationships.
This is not a criticism. Your threads have stood out to me because they have been mirroring a lot of what I have been feeling (although less extreme).
It sounds like your inner self hasn't caught up with what your head knows: that you do need to be happy with yourself, and to have a well-balanced life, in order to a) keep those needy feelings at bay, and b) be a healthy person in or out of a relationship.
Give yourself time, and support.
Going cold turkey, from a life of dates and partying, to a life of evenings in with the kids, was clearly too extreme a decision. Look at the balance of your life: do you have a healthy dose of work, close relationships, and play? You need a good portion of each of these, or you will end up feeling out of kilter.
For the feelings of unworthiness, I'd recommend a combination of therapy, affirmations, meditation, exercise, and personal achievements where you demonstrate to yourself that you are capable (can be small! throwing a party, putting up a shelf... whatever feels like a small victory to you).
Everyone is somewhat shit at relationships, and all the more so when they haven't mastered their insecurities. A corollary to this is that everyone has insecurities, so you don't need to beat yourself up for having them. I think those who are most happy with themselves and most successful in relationships just have a better handle on how to manage their insecurities.
I think a balanced life will help: you'll feel less vulnerable and have a more solid backdrop for the eternal struggle of managing your insecurities.