How will the story go?

I sat in front of my computer yesterday and stared at the picture on the screen. It was a picture of me, Jacob and Kyle taken when Kyle was about 4 months old and Jacob was almost 4. All three of us were smiling. It was summertime and we were staying at a resort on Lake of the Woods. My face was sun kissed and Jacob's hair was blond from all the time in the sun. We looked happy. Life was good.
I look at the picture and think, she had no idea what the next few years would hold. A lot of worry, a lot of fear, a lot of pain and of course, a lot of happiness too. How could we have known that Mel would spend 15 months in Iraq? How could we have known I would have to monitor my health more closely when the doctor found two melanoma cancers on my skin? How could we have known our sweet child would be taken from us before we had a chance to know him? The events and trials of our life change and shape who we are. Sometimes for the better, sometimes not. I wish I could look ahead to what the future holds for our family; of how the story of our lives will unfold.
The last few days my mind hasn't been able to let go of the idea where we go from here? Is our family complete? Do I go back to work or school part time? Do I volunteer? My purpose when I was pregnant was to carry and love Nathaniel for as long as I was given with him. Now I feel like I don't know what my purpose is (aside from caring for the boys and Mel.) I know I need to focus on being the best mom and wife I can be and turn all the love I have for Nathaniel toward my family, but I can't help but think, "This isn't the end of our story. How will our story go?"
I feel like I need to know the long term plan even though ultimately we have no control over it.