I am so sorry to hear about Hannah, Calgeo. I lost my little girl Maude in January this year. She was two years old and just died in her sleep.
To be honest, I don't know if it gets easier, but I do think that every time I fall back into total despair and misery, when I climb out of it I feel a little better than I did before the sadness struck again.
I had a wonderful email from a mumsnetter who told me of how her parents had lost her sibling and who spent the rest of her own childhood in mourning. That email really struck home for me and I was - am - determined that my other children will not have the same experience; that I will value their childhoods as much as I value and miss Maude. It it almost impossible to do this, but even trying to do this helps. I think I read that you also have other children. I cannot imagine how it must be to lose an only child.
Something else that has helped is trying to get back to normal life, however unreal or meaningless it all seems. I now wear make up again and dh and I go out, for meals, to the cinema, with friends, like we used to do before. It is not always a good idea, but the acting cheerful, the trying and the effort has to be better than the absolute sadness.
I also understand the empty arms. I think you should do whatever is right for you as a couple and as a family and take it from there.....
Contact me - CAT me - if you wish.