Looming Sense of Dread

For months, and maybe longer, Madeline has broken out from time to time after eating. We have never been able to pinpoint exactly what causes it. We have cut out things we think might be causing it only for it to happen again. Because we've been completely ineffective in figuring it out, I'm taking her for an allergy test on Friday.

I can not even begin to express the dread that this is filling me with. I did a google search (BAD IDEA) and see awful things like this:

And I just want to break down and cry. The appointment is at least two hours, and I'm dreading every single minute of it. But I know it needs to be done. I'm planning on giving her some Tylenol ahead and time. And I'm going to bring her DVD player and some toys with me to try and distract her.

Once it's done, I'll probably tell her we can do whatever she wants. I know I'll need to be strong for her, but I know all I'm going to want to do is cry when I see her hurting. When she gets upset, she says stuff like "momma - I'm sad and have tears." How can I be expected to be strong through that?

At the end of it, at least we'll have some direction about what causes the reactions so we can start to get it all under control. I guess that's the finish line I need to be focused on. We're testing her for several foods, dairy and dogs, just in case. Ugh.

Anyone been through this with their toddler and have advice?