You may go through a grieving and mourning process much the same as if a beloved person had died. Your grief may take quite a while to work through. Give yourself time. It may take weeks, months, or even a year or two, to complete the grieving process. That is an individual response of everyone and is completely normal.
Denial is a normal part of the grief reaction.
It may help you through the grieving process. As you grieve, you may also feel very intense feelings of anger. Anger at God, at the veterinarian, at yourself, at a family member, or anyone who may be involved with the pet's death. You may feel intensely sad for periods of time. You may feel depressed and emotionally drained.