I totally understand how you feel.

You CAN start B12 treatment NOW... what are you doing for that?

We have a wonderful resource here --the Gluten forum, with a link to this amazing information, that was gathered by a woman who was in your position not too long ago.

http://neurotalk.psychcentral.com/forum13.html

This is her web resource link:
http://jccglutenfree.googlepages.com/

Here is my B12 informational thread:
http://neurotalk.psychcentral.com/thread85103.html

You can only do so much in a day. I'd start NOW with the B12 supplements. After your testing, you can then start on the GF diet.
Other nutrients are lost with diarrhea, which comes from IBS.
One is magnesium. If this gets really low, you can have anxiety and trouble sleeping etc.
Here is my magnesium thread:
http://neurotalk.psychcentral.com/showthread.php?t=1138

Because doctors won't do this for you, we have done the gathering of info for people who are stuck and hurting. But YOU have to read it, and perhaps more than once to learn it.

Each day, you can make some changes in your diet, pantry and life. It does not happen overnight...but when you start to feel better eventually, you will understand how much power you hold over of your health.

So for now, just do the B12 supplements. You will start to feel better soon. That will give you strength for the rest of your journey.