What Causes Vaginal Burning And Irritation After Working Outside?

Hi, I work outside and swear everyday by the end of my work day My private part feels very uncomfortable there is a slight burning.. So it is clearly irritated this had been happening for a couple of days so I went to the gyno they said all they say was a yeast infection.. I have had yeast infections before and they have never felt like that and it s only after working all day.. Any ideas what it could be and how to treat it?