My major surgery was a complete surprise and scheduled in a hurry. It was a lot to take in... believe me, I know how you are feeling right now. I don't know your situation, but I can say although it seems so hard, keep active, eat healthfully and (probably most important) try to keep your mind in a positive, healthy place. When you drift into negative thinking, (I sure did) do anything you can to distract yourself... a walk, shopping, anything that keeps your mind busy and positive.
I'm really a firm believer that if you keep a positive attitude, your body will follow its lead. If you need someone to vent to, PM me... I give some awesome pep talks.