Help with blood test preparation

I have been eating minimal gluten for the past 4 years or so, not necessarily because I suspected coeliac disease, but more so because a lot of wheat containing products made me feel ill.

Recently I’ve been having some bad abdominal pain and nausea and so my doctor wants me to do the blood test for coeliac disease, and after reading up more about it, it seems like there’s a possibility I may have it.

I’ve been trying to increase my gluten intake in preparation for this blood test and I’ve never felt so sick, my stomach is in agony and I just feel exhausted.

Is there anything I can do in the meantime to alleviate some of these symptoms without messing up the blood test, or is it just a matter of gritting my teeth and pushing through the bad symptoms.