Indeed any chronic illness is depressing: think it would be more worrisome if there wasn't a degree of depression. I feel you and am there with you. It's overwhelming what a sufferer goes through.
You might try taking extra d-3 (1000mg/day); they sunshine vit. There are a variety of herbs which can help as well: Ashwaganda, 5HTP, Valerian Root, L-trytophan, etc.. Many of these will help with adrenal fatigue and hypothyroid issues which are common with Candida: particularly Ashwaganda. Ask at your local health food or supplement store and they should be able to direct you to some good products which can to help stabilize your mood.