When my sister, in her mid-40s, died in a road accident the grief I felt was so agonising, yet I wanted it to go on forever, I hated the thought that one day my pain at her death would be softened, that I would not feel as I did in the immediate weeks after her death. I felt she was so dear she deserved to be agonisingly mourned forever.
But only a few days told me that this was irrational and as weeks went by, small blessings came into my life, DS getting into the university of his choice. DD doing well in GCSEs, flowers in my garden, walking through woodland crying my eyes out.
You are only 15 weeks into your loss, of course you feel as you do, but at sometime you need to face up to the fact that life cannot continue like this. That your DH would probably be deeply saddened that his death was bringing you so much misery.
Currently you seem to be almost wallowing in your grief. The day must come when you realise, like I did, that I could not live with agonising forever and I need to readjust to normal life.
Set yourself a date, may be in a few weeks time when you will spend 10 minutes doing something else and doing your best to concentrate on it. Read a book or magazine you love, while curled up with a cup of tea and a biscuit, and slowly over the months, extend that time, or do something similar
Seek help from your doctor or surgery nurse and consider a course of counselling Cognitive Behaviour Therapy (CBT). It works on the principle that your thoughts, feelings, physical sensations, and actions are deeply connected. By changing how you think about situations, you can alter how you feel and behave.
There is also an NHS information sheet on it ['www.nhs.uk/tests-and-treatments/cognitive-behavioural-therapy-cbt/]]