Manual action most likely has to do with your generated content. Try hiring writers to make actual profiles. Some things SEO wise you might want to look into:
https://kikdirty.com/ you are linked into from this link farm.
https://tubesexxxx.com/ and this link farm
https://bestmethodmonetizing.blogspot.com/ low quality link
The Overlander Trail crap link
Camming for Free - Simply click and Enjoy you seem to have been added to many link farms just before the traffic on your site took a shit in Google.
http://local-escort-listings.com/pornstars
Why is your site's header here and many other places? This might be what triggered having a Google employee look at your site manually.
http://www.itsconnection.com/student...page=6&cpage=7
comment spamming... bad idea.