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 provide a measure of comfort during your time of grief.