Now what? life "post" Cancer

As some of you know I have been in a battle with cancer for about 4 years now. I wont get into all the details as they are not the reason for this post. I still live in the shadow of this disease I am due for my one year follow up scan in about a month. So far without fail I haven't got past the one year mark before the cancer is back. To this point I am not having the symptoms I have had in the past so I am guardedly optimistic that I will be found cancer free.
This brings me to the point of this post. I don't know what to do now? I am somewhat limited, because of operations that were necessary to keep me alive, in what I am physically able to do. Again I am not going into the details but stamina, over all strength, frequency of bowel movements etc... limit me in day to day living. Not horribly mind you, I am by no means unable to care for myself but I am no where near what I was when I was diagnosed with the big C. I am only in my mid forties what for most is the point were things are leveling out as far as the who what when where and why's of your life, and I have more questions now then I have ever before. When I was actually fighting cancer it motivated me, it gave me a goal to reach, a purpose, it kind of became who I am...Greybeard, the Cancer Pirate. I am sure this makes no sense to some, why now when it seems that I may have in fact beat this am I more out of sync then when I was involved in the battle or before Cancer?
I am sure you have heard about the soldiers who upon returning to their homes after a war wanted nothing more then to go back. While their lives may have been in danger they understood what was expected, their was a sense of measure ability to their lives that they didn't seem to be able to reproduce back home. Does that make sense? That feels like where I am now.
I have a wonderful family and a great network of friends that provided wonderful support and a safety net for me and mine during all of this. Without them and the unbelievable support of my wife I would not have, or for that matter wanted to survive. I have gained 4 grandchildren (with a 5th on the way) since this all started. I am telling you this to show that I know I am blessed and I am thankful for all of it. So again the question...now what?
I know this is really a question only I can answer and I am not really looking for the answer to the question as much as I am some insight into why the hell I feel this way? It makes no sense to me. I thought before that if I was fortunate enough to get to this stage I "would be whistling zip-a-de-doo out of my ass" to borrow a line from Clark Griswald.
So anyone have any thoughts you would like to share on this feel free to comment.