Never end, heard May coming another one.

The spam update has been a string of updates... one compiling on the next, and the core updates are updates to the "core" function of search itself... these dont "End" they are accumulative and on going as needed to stabilize data and how that data is internalized ( spiders ) and how it is externalized ( serp listings )

I suggest, that your website was hit badly by these updates the best thing is to be patient these updates are contionous changes in your website appearance, the spam update has finished but the core update is still ongoing, so the ranking continues to fluctuate as the core update is completed. Not to make any changes to the website until it is complete. Focus on quality content and update low-quality or spammy content. This is one way to overcome and rank again your keywords.