Hi chimera. I am so sorry for the loss you feel. It must be so challenging. Anger is one stage of grieving. The 5 Stages of Loss and Grief | Psych Central

One way out of this series of reactions is to have a therapist that specializes in coping with grief to help you move towards a reconciliation with the loss of your dad and the anger towards your mom.

If for any reason this is not possible then you may find these articles a place to start.
On Grief, Loss and Coping | Psych Central

Grief and Loss | Psych Central

You may also find these support groups are a way to move through the stages of grief.
Grief and Loss: Support Groups | Psych Central

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