I understand your heartache; although it's been several years now since my wife, Ruth, went home to be with the Lord, not a day goes by without my thoughts turning to her and the many years we had together. And yes, holidays are especially difficult.
But I take comfort in three great truths, and I encourage you to do so, as well. First, I know she is safely in heaven, far beyond the pain and suffering she often endured here. She is now in God's presence forever, and although I miss her greatly, I know that someday soon we will stand together before the throne of God. For her, Jesus' promise has been fulfilled: "My Father's house has many rooms... I am going there to prepare a place for you" (John 14:2).
I also take comfort in the fact that I'm never truly alone, because Christ is with me every moment of the day. I may not always feel His presence, but I know He still surrounds me with His love. And this can be your experience, as you turn to Him in prayer and in the Bible every day.
Finally, I take comfort in the fact that God still has a reason for keeping me here -- and He does for you. No, you may not be able to do everything you once did. But you can pray for others, and you can encourage those around you by your smile and your love and concern. Keep your eyes on Christ, for He gives us hope.