To make sure you aren't punishing yourself by overlooking at his history and comparing. By making sure you aren't becoming depressed by using the internet to increase your sadness or anxiety. By using your phone as a means of contact. Your buddy can have a list of triggers words specific to you so when you trigger or have a bad day they know to reach out to you and help you so you arent isolated. This in no way should be given to a person who is hurting you or refusing to help himself. Betrayal trauma is no joke tho and needs regular self care. You should be doing things for yourself at every stage of grief.