My thoughts are with you worried dad, I'd be terrified too in your shoes. You have been given lots of great insight here and we all want to help in anyway we can. I was relatively young, 37, when I had my surgery and my recovery was surprisingly easy. Feel free to private message me if you want to discuss my experience. I do agree that your son will greatly appreciate you being positive and enthusiastic about his surgery and recovery, and I don't presume to know what you are feeling. Be strong, you are one of the most important people in his life, a role model, parent, friend...Be a strong advocate for him while in the hospital, don't hesitate to question the staff, they are there to help make this as easy as possible, most love their jobs and are often underappreciated.
Phil