Seth,
With my surgery on the quickly approaching horizon, I must say I can certainly relate with the situation you are in right now. I also feel like I have been living it for the past 4 years since I've found out I've had this condition and knowing that, one day, I will have this surgery. When I first found out about it, I had the same questions as you: why me? what did I do? I have also been through the same quagmire of ups and downs, rationalizations and realizations. My mind raced through scenarios and bounced between such extremes as 'It has to happen to someone, and it could have been much worse' to 'maybe my path through this life is to leave my son without a father so he can get some kind of experience from it'. It's an emotional roller coaster that I wouldn't wish upon anyone.
When it came right down to it, I just decided to treat it like any other experience in my life: learn and live. Try and look at it from outside and examine your situation as you would if it happened to someone else. There is a lot of knowledge to be gained from seeing how you react to intense situations. I bet if you look closely, you will find out how much courage, foresight and integrity you have that you didn't know you did. Think about what you held close when your time came, when you had that clarity and agreed to the surgery. The self-examined life can be a wondrous thing.
Personally, I use times of transition such as this to affect positive change in my life. Getting married meant getting healthy and getting back to school. Even smaller things like changing jobs, I've learned, helps me change habits (before I recognized this, sometimes it was for the worse).
This will not happen overnight. There is still a large emotional element that is attached to this event, and as others wiser than I have stated previously, that will take time to pass. The only way to get through that is to surround yourself with people that you care about, and that care about you. If they truly care about you, they want to help. I, as well as many of us on this forum can attest to, know that this is an exceptional burden to carry, but love is all about sharing burdens.
Regards,
Joel