Google penalized and sandbox my website
My website is not ranking in search result and no increase in traffic from past 5-6 months. I have been working on all seo factors, but still it is not ranking well. When checked I found my website is penalized and sandbox by Google and massive drop is seen (sharing screenshot below)
From the month of July as seen, my website traffic has dropped even during Possum update and till date no reflection is seen. Kindly suggest factors how to remove website from sandbox and increase ranking in search result.