Grief is obviously an actual thing.
But, boy, oh boy, oh boy, can the term be used to perpetuate grievances, self-pity, and endless rehashing of the long-gone past, stemming from a refusal to accept loss, vicissitude, hardship, or adversity.
The model for this is Miss Haversham.
So, yes, I grieve, but I refuse to indulge in self-pity.
Life's too short to be miserable.