I am so sorry to hear of your great loss.
Recently I lost my dear mother, and found
great comfort in the Holy Bible, like at
Isaiah 25 verse 8 - "The Sovereign Lord
will swallow up death forever, and wipe
away the tears from all faces." Also at
Revelation 21 verse 4, we find God's
promise to remove both pain and death.
I hope these verses will give you a
measure of comfort during your time