The five stages of grief are not absolute truth. Like all theory, it’s based on a hypothesis (an educated guess). There is a bit of research to support the theory, but there is also a bit of research to contradict the theory. In reality, other grief models may fit your experience exponentially better than the ‘Kubler-Ross Model’.
Five Things About the 'Five Stages of Grief'
Good look at some issues that go with grief and Kubler Ross Stages
Please also review AIHCP's Grief Counseling Program