How do You Let Go?

Sometimes I wonder if I'm ever supposed to let go of a love.
Even when that person has hurt you so much, you still want to be with that person.
When your view of life, is that of despair, and loneliness, yet you try and nothing seems to work.
Your scared of rejection, so you don't move into the dating work, but yet your lonely, and want someone to love, and to hold.
Someone to love and hold you.
So, How do you let go?
Why is it so hard?
You want Love to come knocking on your door so bad, but your afraid to answer it, if it does.
Some people say, don't look for love, just let it come to you, but that doesn't always work.
When is it time to let go?
Why is it so hard to let go?
How do you let go?