So sorry to hear of your loss. Please take the advice of some wise posters who say that if you need to reach out to someone do so. Your fiance would want you to keep her memory alive by sharing your loving memories of her with others.
Nothing I can do or say will take your pain away & you will need to grieve in your own way, in your own time.
Only by doing so will you keep her in your heart forever.
I pray for you & her family. May you all somehow find peace.