What's the best probiotic ?

I been looking into curing candida overgrowth. I been having health issues and my mental health all sudden got worse. My doctor could not find any illnesses. I came across, Candida and the symptoms I have like 90% of them also the impact on mental health sounds like me. I came across a free test you can do "saliva test" and within seconds that water looked scary just as the picture said eventually all floated to the bottom it looked bad. So I clearly have a candida problem. I came across how probiotics can cure this and can also cure a lot of mental health problems. But what is a good probiotic ? Where can I buy it? Walmart? Etc also any in gummy form? I can't swallow big pills 😞 thanks!