Iodine to blame?

I have been diagnosed with Iodine deficiency, SCANT growth of candida parapsilosis, slightly estrogen dominant, slight adrenal fatigue/imbalance. I have been on a diet with no dairy, no refined Sugar (hardly any Sugar at all besides fruit), and no wheat, for a LONG time. I exercise every day and count calories. I cannot for the life of me lose a pound. I have also been struggling with quite sever constipation for many years. The rapid weight gain of about 25 pounds came on after one year of antidepressant, birth control, and corticosteroids (all of which I have been rid of for over 2-3 years), also came on AFTER I cut out dairy and sugar. Lots of cellulite and a very bloated tummy.

My biggest question is which of these is the biggest factor?? The estrogen, the candida, the iodine, or something else entirely?? What can I focus on first to lose weight? Am I hypothyroid? Insulin? ( I also get Sugar crashes daily). Is there an underlying problem with the liver? I spent years on pain killers before all of this. Sorry for the rant, I am at wits end. My friends and coworkers even comment (somewhat politely) that I should weigh less considering how healthy I am! Thanks for any info!