I'm sorry you are struggling with this. Are you familiar with the concept of complicated grief? Here are links to 5 articles, from PsychCentral's archives, on the subject including a quiz you can take to determine if you may be experiencing complicated grief:

What is Complicated Grief? | Mental Health Awareness

Complicated Grief Requires Attention

Complicated Grief: How to Get Unstuck | Bonding Time

New Insights on Grief Recovery

Grief and Loss Quiz

My best wishes to you...