Don't know what's going on

Vanessa
Hey ladies so for the past week or so anytime I eat/ drink something that has sugar in it. I clam up and light headed and don't feel well for a bit after that. I was tested 2 times for GD and passed. It really scares me because then I start feeling my anxiety coming on which leads to an anxiety attack. Does anyone know what this could be caused from ☹️ I talked to my doctor and she didn't really say too much about it. I'm 36 weeks and 2 days..