For most people, grief slowly integrates: it stays real but stops running everything. For roughly one in ten, it doesn't. That's sometimes called prolonged or complicated grief.
Signs: intense yearning that hasn't eased after a year or more, an inability to accept the death, avoiding everything that reminds you, or organising life entirely around the loss.
This is not weakness or a failure of love. It's more common after sudden, violent, or ambiguous losses, and after losing a child or a partner you built your whole life around.
It responds well to specific therapies — complicated grief treatment, and some trauma therapies. If you recognise yourself here, that's worth a conversation with a professional rather than more time alone.