Lost all traffic after core update

Hi! So I have a website for my wifes local massage salon. After the core update we went from place 3 to place 100 on the most important keyword. It started going down on the 18th and went back up the 19th and then to the 100th place and didn't recover. It is called Relaxed met Roos. I have created it with WordPress, am following all yoasts suggestions and everything was working pretty great, until the update. Has anyone ideas why or what i can do to get it fixed? My wifes business greatly depends on local organic traffic from google. But it is small so we don't have the means for a professional website builder or seo campaign. Please help!