How do I let go of my past?

You are asking a million dollar question and the only real answer I can get
Is time
Some say jump into a new relationship ,change locations ,even jobs
abandon all the friends you have joint friend ships with ,,what if its family

Not allowing yourself to keep going there is a huge part
Keep going over and over it with could have ,would have ,should have only keeps it fresh and renewed in your mind (this is my Mo)
When you quit smoking they tell you to change all old habits ,,normal triggers that you normally feel the urge to smoke ,after a meal ,while sitting at your PC ,and even the chair you normally sit in ,,,change your routine

But getting over the loss of my best friend and someone I have been Intimate with ,shared all the secrets of my life with ,shared family experiences
changing chairs and routine can't fix that .

I say its like a death same grief ,except mutual friend comfort you when its a death ,,they avoid you when its a break up
When they die you look at photo's and have found memories
When they break your heart ,,you have to hear how well they are doing
the guy she is with is a really good guy ,pic's of her happy on face book
and in my case avoiding family functions because the family still invites her
and they just expect you to get over it and move on

Because of my family doing this ,always trying to force me to accept her back into my life ,telling me not to put them in the middle
only shows how little my family cares about how bad it still hurts

She has her own family ,now she has mine too
So 7 yrs and I am still missing family functions 2 this month
and now Thanksgiving is coming up ,and now they are forcing the issue
she wants to come ,,she misses the holidays with my family
I gave her most of the birthdays ,now she wants my holidays too
I have explained to my family I need more time ,,,,she made a choice
She has her own kids now ,she has her own family ,,,but no one gets it
She almost destroyed me ,,,I am not ready to be friends again
Its hard for me to move on to begin with ,,my family has made this even harder
So if you find the trick ,,please tell me ,,I am still dealing with it myself

Habits are very hard to break. Withdraw is a bit@h!