It's hard writing to someone without a name or gender!
Dear you,
I want to say that I can feel your grief and your pain. I agree with the nurse, you should have grief counselling. It's not something you can be ready for. You just have to do it.
You are asking for help, and you know you need it.
You've nailed it: it's not healthy, you are depressed, you are resentful and angry. This man's passing is dragging you down. You want to live.
You may even be clinically depressed, and I wonder if you are getting treatment for that. I have had depression all my life, only I didn't know it at the time. My youngest child, age 30, got antidepressants following the passing of his father's death, and it has helped. This was a trigger for him, you see, and it was for me, as well. I was divorced and remarried, and my 2nd husband had cancer surgery at the time my 1st died from his cancer treatment. It was tough for all of us.
The professionals can determine if you need treatment. There are so many wonderful treatments for depression. You have a life to live, you have things to do. We manage hubby's cancer and try to enjoy each day. What's done is done. I use Cognitive Behavioural Therapy to try and let go the things that do not matter. It's a tool I learned. I needed more than just tools though.
Grief is very complex. There is a difference between grief, bereavement and mourning. They are all parts of getting through this. 
You get on that phone and get some help. People care about you. Please go and get some help.
I wrote this article a few years ago:
On grief & grieving
Grief, mourning, bereavement
It is said that we can demonstrate that we loved well by expressing our grief. Grief is a normal response to loss.
Being in mourning, we go within, and look after ourselves.
The bereavement process is one that differs for all. The state is bereavement means you have experienced a loss, which can be a person, place, home, job, family situation.
Mourning is the process by which we honour the life, not the death of a loved one. We look back and share their stories. Depending upon culture or religion, we have particular ceremonies and practices to help us with this event.