Grafts, flaps etc. usually fail really early in the process. The main causes are a lack of proper vascularization and infections. That being said, once you are as far out from these risky parts of the process, the transplanted tissues failing is a remote possibility. Poor blood supply is discovered in the first 30-60 days out. and infection risks pretty much go away when the thing has fully taken. Hopefully this will take the edge off your worry.
As with all of us recurrences are a "other shoe always waiting to drop" kind of thing, and you have to learn to let that be part of your life, live with it proportionately, without letting it BE your life. Obviously, this is easier said than done, but if you are ever to have peace in your life, you have to learn to embrace this part of the new you.
Staying away. We have people leave these boards, not help those behind them, exactly for the reasons you do, (no harm no foul) and that is often because being involved in the dialog is a constant reminder that what is happening to them could be happening to us/you. I initially found that very difficult, since the first go around was such a disrupting personal experience, I was feeling vulnerability and shock, and I didn't want to feel it again. Truth is, hiding from a reality makes it no less real.
I would just like to say that there is another side to the coin. There is not a day that goes by that I do not find inspiration in the messages of others, not a day that I do not learn something from someone else, not a day that I do not give thanks for still being one of the lucky ones. Those things make it possible to put the fear and uneasiness in perspective. Involvement in other's battles allows you to do something that is part of any life that has true value; and that is living part of it in service to others. It connects you to your humanity in a profound way. It is the path. Your post shows that you are a highly religious person. When you make your decisions, I hope that you will let that guide you in choosing to come back or not. The dictates of every major religion speak greatly to helping others, something that you are more than qualified to do at this point in your life, and which so many others need.
Know after that little univited slew of words, that if you decide only to come back to ask for things, there are people here that will always be willing to answer your questions, and hopefully quell your discomforts.
