Another way to say that you are grieving is that a part of you is stuck in a moment in time.
Sometimes the cause of the stuckness isn’t the grief itself, but the fact that you don’t even recognize that you’ve lost something and that you need to grieve.
Grief is a word that is used interchangeably with bereavement, but grief is not exclusively about the physical death of a person.
Grief doesn't fit in a box, either. Some forms of grief take years to work through, other types take a few solid months, some take a single moment of deep acknowledgement.