Yeast infection

It’s my second time having a yeast infection , the first time I was in denial because I thought I had just shaved and that’s why it was itching. I’m not sure how long it lasted the first time but this time around , I caught It from the beach water. How long is it supposed to last ? When should I start freaking out? Is vagasil ok for it ? It’s going on a week since I had it and it’s gotten better , but is that normal? Pls help !!!