No links purchased, i disavowed 2 poor links but no resultsHave you purchased any links recently? If yes, then check the quality of the links. If you find it poor, it's best to remove them and await for the results.
No links used or built, a few that came naturallymaybe anchor over optimizations?
No, i've done it after getting hit, i remember i tried 301 with other domain, after sometime new domain also got hit.You could experiment with a 301 later on but no guarantee
Did you disavow any links prior to getting hit?