Do I need to file taxes now on a settlement received in 2018? Estimate taxes? Do I need to amend 2017?

I filed my taxes and received my refund for 2017, then unexpectedly received a settlement in a discrimination complaint.  The employer deducted taxes for the lost wages portion and sent a separate check for pain and suffering.  I have not received a 1099 & the payment was received in Feb. 2018.  Do I need to pay taxes on this portion?  If so do I need to do estimated taxes now?  Do I need to amend my 2017 return?