My husband died suddenly at 56 exactly 20 years ago before any of our children married or any of our eight grandchildren were born. One doesn't get over the sadness but one does learn to live with it.
Calendar filling is a great help, do things, get out, travel, have something interesting to tell your friends: Sing for your supper, if you are only a wet blanket you will not be asked again.
One friend who was brilliant at going to the cinema with me suddenly hurt me badly by saying "Oh I can't go to that with you, Husband wants to see it."
Another asked me to lunch and when I suggested the following day instead she said " Oh no I can't then because Husband will be at home".
Ouch.
To well meaning friends I'd say spaghetti on a Monday evening is a delight, so don't hesitate to ask and don't even think of trying to find a table partner, just do it.
Two widowed friends were writing a practical advice book for new widows and I said "Tell them to buy more knickers" because of course the laundry does not need doing so frequently. I was quite cross that they didn't include this useful advice.
However what we did agree on is that year three is the hardest, so be warned. Everyone imagines you must be "over the worst" but actually you have finally, totally run out of energy to hold yourself together, to be brave, to manage and you just want to curl up and moan that you "do not want to play this dirty rotten game no more..." But there's nothing for it, so just do your best and it does get easier eventually.
Good luck!