Same thing happened to me when i'd have even a small amount of freshly squeezed citrus and/or fruit juice. I was weaker than on the WF, and many times felt like my heart would explode in my chest. Took me a whole week to figure out that Vegetable Broth without garlic worked best to re-nourish and strengthen me.
Took some trial and error and much advise from this forum to figure it out, being that this was my first WF.