My experience with chelation is similar to yours. Going through chelation taxes the body tremendously due to how badly the liberated heavy metals feed candida.
One's metabolism deals with excess of heavy metal by storing them into bones and tissues, and this simply because if they remain in the blood stream it is deathwhich ensues. A huge part of the candida protocol is to clear these heavy metals out - while allowing the body to keep coping. My solution has been to take breaks - do the cleanses diet + antifungals while alternating the kidney/liver/bowel cleanses. And allowing for breaks in between to let your body resume its equilibrium and store some nutrients it needs before starting over again.
I was completely heald of candida (or so I thought) and back to a normal diet. It came back recenty after a few months and I believe I still have a bit of chelation to do before I can be completely healed of systemic candida.