I'm so sorry for your loss. I know how hard it can be -- my mother passed away two years ago after a prolonged battle with stroke, heart failure, and brain damage, and she had just turned 63.
The pain was pretty unbearable, and it seemed to get worse as the months passed. I eventually sought out the help of a therapist. I was skeptical at first, but they really helped me get through this. Sometimes it's hard finding a truly good therapist -- I had to try a few before finding someone I could relate to, and could help me work things out. (Also, if you're comfortable, and you feel you need to, there's no shame in using anti-depressants).
I can also tell you I was really angry for a while too. Angry at myself, angry for not spending more time with her, angry at friends and my wife for not really understanding what I was going through, angry at God and the universe. It's a dangerous path, because your conscience starts telling you how wrong it is to be so angry -- which just becomes this vicious cycle of becoming even more angry and down with yourself.
But what you need is someone to tell you it's okay to be angry. Friends, family, therapists, whoever. You don't need them to tell you things like your loved on has moved on to a better place. Not that they haven't -- it's just that most people in our position generally aren't comforted by those things.
Another thing that was hard: going back and forth between wanting to be left alone, but at the same time still needing companionship. It's a tough thing to balance out. You need to give yourself space and time alone, but at the same time be careful not to push people away.
This is where you find who your really close friends are. Confide in and open up to them. Let them know though that you don't expect them to say anything comforting -- you just need them to be there, sympathize a bit, and be patient with you. But when you're with larger groups, it's probably a good idea to keep your emotions more bottled up -- and focus on just trying to enjoy yourself.
I often found it hard to do that, or to find joy in anything. I found myself feeling guilty about wanting to feel happy, or doing things just for fun, enjoyment or pleasure.
But you have to get past that. One thing I found myself feeling often was, there was no point to life. Maybe there's some truth to that. But we're here now living on this earth -- and one thing I've learned was, one of the simplest but most profound points of life is to just find and experience joy and pleasure. (Of course, as long as it's not at the expense of others. I think the hard thing there was realizing, I'm not doing this at the expense of my loved one who has passed).
Along those same lines, I found it very helpful often to focus on the happy times -- on the fun, happy, loving memories you have of her. It's easy to dwell on the sad parts, or when you were angry with each other, or the points in time around their death. Try to push those out with the positive memories.
I think that's a key way of coping. There's a part of you that almost wants to forget, because it's too painful to remember. You look around, and see their pictures, their belongings -- clothing or unfinished projects. You see places you've been to together, and the memories can be really unbearable.
But there's a much bigger part of you that wants you to never forget, to remember every little part of them. The only way I've been able to reconcile the two is to celebrate all the great times you've had together, and to be thankful for the time that you did have together.
Which brings me to my last point -- faith, religion, spirituality. Yes, I know, a very sensitive topic. But I don't want to talk about it in a conventional sense. In fact, what I found was that my traditional faith and religion actually made things harder for me, and brought me little if any comfort.
Things only got better for me by broadening my perspective. I had to read and learn about other perspectives -- whether that was other cultures, philosophies, etc.
So my suggestion here is to try and go beyond what your accustomed and comfortable with in this area. If you're not religious, maybe investigate it, or do more of a broader, non-religious but spiritual search. If you are traditionally religious, try to look at other perspectives. I know I found at least some comfort in this -- at the least, there was comfort in knowing that people of all sorts, from altogether completely different times and places, have been coping with the very same things.
Hope this helps -- sorry so long and rambling. Best of luck to you.