Grieving involves coming to terms with the loss of something a person holds as important or special. Although grieving is mostly associated with the loss of someone who dies people also grieve when for example a relationship ends because their partner leaves or where a parent disowns a child and vice-versa.
Everybody deals with grieving differently and the best way is to take ones time, be surrounded by positive people and take each day as it comes and finding reasons to be strong and understand that some things will happen outside of ones control.