My recommendations were broken by Shaker

About a month ago, I sent a Shaker link to a friend. He opened it and tried to connect his Spotify account, and somehow all his songs ended up in my Favorites playlist. It completely messed up my playlist and recommendations. I deleted all those songs, but the recommendations are still terrible. Please help me reset my recommendations. I’ve been trying to fix them by liking and disliking songs for a month, but it’s still really bad.