Life can be pretty tough sometimes. It will beat you down and leave you in shock without any apology. Let's be honest, life can be a total B#@$%. I think the hardest thing about it that will get to you, is the element of surprise and uncertainty that it brings. In an instance, things can change and plans can become nothing but dust in the wind. It's hard, and I wish it didn't have to be that way. But it does. That's how life goes. It's the good the bad and the ugly, and often times, the ugly overwhelms us and blocks our perspective from all the good.
When you lose something or someone you love, the shadow of loss will cloud you. But given the healing of time, and hopefully it's sooner rather than later, you'll have the vision again to realize all the good that came before. You got to have something or someone to love, even if it wasn't for as long as you would have liked. You had good, wonderful memories, and in time, you'll be able to smile looking back on them.
It may hurt, and that's okay! You're human and sometimes we all need a good cry and at least a solid 1/2 pint of ice-cream ;). Let it out and acknowledge the hurt. But also acknowledge time when it starts to bring about healing in your life. You might not want to move on, because you don't want to forget or accept that you have to leave something behind, but you need to be open to what's ahead.
It will be different, and it will be an adjustment. But if you open yourself up to the good that life can offer, you'll find something or someone to love again. You'll be able to make more good memories and have happiness in your life again. It will just be a new happiness. Perhaps even a better one than you could have anticipated. But the key through all of this, is time. Give it time and give yourself time.
I'm sorry for what you have to go through, and I wish life didn't have to be so hard. But I'm not sorry that you've loved and that you've lived. And I hope you aren't either.