I am getting excessive canker sores along its what i think is a yeast infection. immune system? yeast overgrowth?

Common: Canker sores are common in young people particularly when under stress. They're caused by a virus. Vaginal yeast infections are exceedingly common particularly when hormones cycle during periods. The two are unrelated. These are not typical infections in people with immune deficiency.

See your MD: Excessive canker sores & yeast infections may be your body's way of signaling that your defense systems are being attacked by either bacteria, yeast or a virus. It would be most effective for you to see your md to have the appropriate tests taken. Please also relate to your doctor if you have been taking any medications, been exposed to anybody chronically ill or been traveling outside the country.