Do we really get total closure especially from someone you've really loved since childhood? A resounding "no" would be the only answer.
How would you put an end to loving someone all your life? May be concentrate on his flaws and his many uneventful excuses that you know were superficial. Or even better: that you've realized you will always be under the covering of God's faithfulness ; and that He is not going to allow you to be that prodigal daughter that He loves unconditionally be lost any longer...
And though forgetting is hard, forgiving yourself is one great wisdom you may begin to adhere. Remember : Closure is not a conversation between the two of you and saying your goodbyes; not e-mailing each other and say," I'll always love you," (though it's true, it doesn't cut the truth partially); but real closure for me is a spiritual and a personal decision. You owe yourself that choice---to choose not to be in bondage and letting it all go.