why can't I be as positive as everyone else

EVERYONE is being positive. They're either just hiding their true feelings and fears from me, or they honestly believe that we're out of the woods and Bug will be a perfectly healthy baby girl.

WHY?!

Why can't they see that we aren't in the clear?
Why can't they see all that can go wrong?
Why can't they see all that we still don't know?

I feel like the worst mother-to-be in the world.
I am hopeful that Bug will be here in November. I'm praying that she'll be as healthy as she can be. I can't get past the cystic hygroma though. She has this and there's no way to change that right now. She may need surgery as soon as she's born, if she's born healthy enough for surgery.
There is still a 50% chance that she won't be here and no one seems to see that. I can't forget that.
I love Bug. I want to run out and buy her cute little outfits for next summer (clearance sales are the best!) and a new pack n' play (we have no need for one, but *I* want it for her) and a bedding set and pick the colors for her room. I know it's still early, and most people don't know what they're having this soon, but I do and I want to spoil her.
But I can't.
I bought a bug toy. I was so hopeful when I bought it, and I smile so big my face hurts when I see it, but I can't bring myself to buy anything else. I want to bring the bug to the hospital and play it for her when she's born and for her to have it always, but that's something small and something I can do. I can't buy clothes because I can't guarantee that she'll wear them (the few clothes I bought before May 12 are gender neutral and can be given as gifts) and, knowing she's a she, I can't buy her something and picture her in it and then not be able to see that picture in person. Even the thought of not seeing the picture in person hurts. I keep thinking of my favorite outfits that Belle wore and then I think of Bug in them and I cry.

I want to be as positive as everyone else. What's wrong with me that I can't?