Do you know the writer and scientist Elizabeth Kübler-Ross? Her books about grieving are famous.
She describes 5 stages in grieving: Denial, anger, bargaining, depression and acceptance and she even dare to give a running for them, six months, however, she herself stressed on the idea that this period of time was only average and that the five stages are not lineal in time. Maybe, you could have a look at what she has written about and see if there’s a motive by which you can’t reach the final stage.

Do you think that writing a letter to your best friend and tell him/her everything you want to tell could help you? You could also try with your parents.