Be present and go through it. Go through it all. You need to be able to move forward and the only way to do this is to experience the pain, loneliness, and loss. Sit with each emotion including anger and face the ugliness head on. Until you do this, you will not be able to move forward. If you do not deal with negative emotions, you will find other ways to cover the pain.
The good news is that when you become aware of the emotions that have a hold on you, you will also be quick to know the emotions that trigger the memories of the past.