I'm sorry for the things you've got going.... and for the concerns that you have. We are human - so worrying is natural. But it really can put us in that dark place and rob us from living and being present each day. The only thing I can say is to just *try* to take it day by day - and not look too far forward. Usually, when we think of the worst case scenario - it tends to be far better than that (usually, that is!).
I wish I had all the other answers. I don't. I have moments where I'm just as frustrated as you and just as depressed.
The others have offered some good thoughts and advice. I wish I had more to add.... but I do empathize w/ what you are saying. I have a strong feeling, though, that you'll have a beautiful wedding... and we'll all pray that your pain issues - at least for that time period - will be as low as possible.
Hang in there, Mindy. Keep venting as needed and know we are here.