We are going to be like your mom and say “no you can’t have this or have this”, so its up to you whether to add blueberries to your diet.
15 blueberries is about 8g of sugar so it is rather low in sugar. Blueberries also are anti-inlammatory, contain anti-oxidants, and have a bunch of other health properties. I’ve had them throughout my treatment without any problems whatsoever.
On a side note: I would consider not running so much during the week and consider reducing it; you need as much rest as possible to recover from candida and exercising could be taxing your body too much.