Few events in life are as painful as losing a spouse, and God understands your grief. He even understands your doubts and the other feelings you have, and I want to assure you that they do not change His love and concern for you.
But more than that, God wants to comfort you and help you deal with your loss. Don't cut yourself off from Him, even if you find yourself confused by what has happened to you. Instead, turn to Him and tell Him honestly how you feel -- and then ask Him to help you as you adjust to the loss of your husband. The Bible reminds us that He is "the Father of compassion and the God of all comfort, who comforts us in all our troubles" (2 Corinthians 1:3-4).
No, God didn't answer your prayer the way you thought He should. But He did answer it -- because now your husband has passed from all the pains and sorrows of this life into the joy and peace of heaven. His cancer is gone, and he is now safely in God's presence forever. In heaven, the Bible says, "There will be no more death or mourning or crying or pain" (Revelation 21:4).
God's love for you is just as strong today as it was six months ago, or 60 years ago. The proof is Jesus Christ, who was willing to give His life so you could be with Him in heaven forever. Now more than ever, put your faith and trust in Him, and thank Him for the hope we have of heaven because of His love.