Sometimes the strongest thing you will ever do will be to let go of someone. It will be painful, you will suffer guilt, and you will second-guess yourself, but for your own sanity and quality of life, there will come a time where you hand them to God, with your love, and trust Him to be who and what He is. May our Lord comfort you.
Sometimes the door closes on a relationship, not because we failed but because something bigger than us says this no longer fits our life. So, lock the door, shed a tear, turn around and look for the new door that's opened. It's a sign that you're no longer that person you were, it's time to change into who you are. It's going to be okay.