Does vitamin C response prove SIBO

I am currently experimenting with high dose vitamin C. I am taking around 10g/day, divided into hourly doses. I am not certain yet, but it seems my anxiety seems to go away when I take a certain threshold amount of vitamin C. I don't seem to benefit unless I'm taking around the bowel tolerance level. I am speculating the reason for this is that vitamin C is absorbed by the small bowel and only does me good when it reaches the ileum (lower small bowel). Maybe when I take a litle bit too much it spills into the colon, causing diarrhea?

My question is whether response to vitamin C loading as described above is diagnostic for SIBO? My guess is that vitamin C is more likely to kill bacteria than Candida. Anyone got any thoughts on this? I am in a real pickle at the moment. After doing oral HPI I am suffering huge anxiety, something that has never been a real problem for me in the past. I can now empathize with anxiety sufferers. I have suffered from Depression for a long time, which I always thought was the worst disease in the world, but I can say now that high anxiety 'ain't no picnic' either.

The reason why I need to make this diagnosis of course relates to treatment. Unfortunately most effective treatment options for SIBO are counterproductive to controlling Candida, or have potential interactions with systemic antifungals.