I've been through terrible grief that lasted years. I thought I was going to die. One time I actually almost did. So what I'm going to say comes from experience.
What is grief? Grief is intense sadness over sudden separation.
First... the grief has to be felt. If you need to cry every day and be a total wreck, you should let yourself do that. Try not to self-destruct by doing bad things to alleviate the pain. That will make it turn into "complex grief" (a psychology term), which is when grief becomes attached to other problems that you created in order to try and make the grief go away faster. It doesn't work, it just makes you more unwell. Also, is it not a reflection of the love I'm going to talk about below. You want to be really good, gentle and kind to yourself. Okay? The grief hurts and it's 100% normal. You don't need to stop it.
I know this sounds like a psychological trick, but I'm serious. When your lover was alive, you loved being with her, spending time with her. When she went home or went into another room, did you grieve her? No, you still related to her as though she were alive. She could fly to the other side of the earth and although you'd miss her, you'd still feel connected with her because you were relating to her living form inside of you.
I would like to suggest that your separation from her now represents a change in your relationship, and not the end of the relationship. She has a different form now... perhaps nothingness, perhaps as a spirit. You can conceive of this however you want, just like when she was alive but in another room. The people in our lives are not around us 24/7 but the relationship continues even when they are somewhere else. Death is no different. You may not see her again in the flesh, but you are still relating to her, even as you write about her here!
I also suggest investing your time and energy in things that get you outside of yourself so that you don't dwell too much on loss. You need to take stock of what else is available to you, what else you can be grateful for, so that you know there isn't just loss, there is also abundance in your universe. The best of these is doing good deeds and helping others. Volunteer for the less fortunate, or for a cause. You can dedicate every good act to your dearly departed love, knowing that she would thank you so very much for helping others in her name.
You can also put energy into learning a new talent or art form that helps you express your grief, or just take your mind off of it.
Surround yourself with friends and good people who care about you.
What is the theme of all this? To show yourself that love never dies. Love is a universal energy that moves through everyone and everything. The forms it takes on appear and disappear, live and die, but love itself never dies. It is always reborn, every day. If a form that you love leaves the room, love doesn't die. Another form will arise. You yourself are made of that love. Every cell in your body - billions of them - are all interconnected in infinite ways, working together, keeping you alive. Other people are part of a supply chain that brings food to your mouth. The roads you walk on, are made by the hard work (love) of people who want to keep us moving, traveling toward one another. The air you breathe is thanks to countless living beings putting oxygen into the atmosphere.
Eventually, you come to realize you are grieving a form, but not the essence of the form. You honour the form that is lost, you "namaste" that form, you always remember her fondly. Then you put your energy into new forms that connect you with the essence of life again.
When you grieve a form for too long, it pulls your living energy into the energy of death. All living things must die so that new life can be created and that is worth contemplating, but you're not dead yet. You also haven't lost the only form of love in the universe. There are many forms beckoning for your acquaintance, in every day simple things. There is also your own inner eternal form of love, of inner peace and tranquility that is your true nature. Meditation can show it to you. I think you'll find that, with time, you will even come to see how your relationship with your departed love is reflected in the new loves all around you. They all come from the same source!
These are some of the lessons I've learned from horrific grief. There are gifts in it. The grief is showing you your own aliveness, the depth of how much you loved. If you loved deeply, then you will grieve deeply. It is showing you your own humanity and depth of feeling. The nature of the heart is dual. When we feel love we cry because love is bittersweet. You can't know love if you don't know suffering. If you try to silence the pain you will just silence the love. You have to feel both to fully embrace what it means to be alive.