Itchy after sex after swimming in a lake 🙆🏼

Hey ladies! My boyfriend and I recently went swimming in a lake, then had sex shortly after. We hung out after the sex and then I left and hungout with other friends so I didn't have time to shower. Now I'm itchy down there. I showered immediately the morning after (yesterday) and it resolved, but woke up with the same issue this morning and cleansing didn't help. Tips?