What should I do with this dead website ?

Hello, 3 months ago i created 2 websites for ecommerce. I did a great SEO on page work, they strated to ranking well. 1 week ago, i did a mistake by linking these 2 websites. Now they are loosing a lot of their keyword and don't have any traffic left. What should I do ? Continue to post blog ? Sell cheap link with ? Any suggestions ?