HELP.. ANSWERS PLEASE

ok so i’m 17, very healthy, and sexually active. so im a lifeguard so i’m in a swimsuit all day.. but i have this problem when i produce A LOT of my white creamy discharge i tend to get itchy where the discharge is making contact w my skin down there. it happens like once or twice every other week. i’ve gotten tested for std/sti twice, everything came back normal. does anyone else experience this??? if so, how do you handle it?