security for attacked centOS server

i have small centos server i see its CPU 130% and high usage on bandwidth i am sure its attacked but haven't idea how to stop this because i receive this 5 warning from my data center one of this warning belolw i want stop this from my server and protect my server in future In the last 90 days: 1 repetitions Action: This IP address will be blocked during 8 hours. Evidences: (2018/09/09 13:49:00, Time zone: CEST (GMT +02) - The last 100 lines of 4114 hits in the range of 5 minutes) Sep 9 13:48:57 [login to view URL] %ASA-4-106023: Deny tcp src nudo34-192:[login to view URL] dst nudo61-128:[login to view URL] by access-group "nudo34-192-2" [0x7200cbe7, 0xc20d25c] Sep 9 13:48:57 [login to view URL] %ASA-4-106023: Deny tcp src nudo34-192:[login to view URL] dst nudo61-128:[login to view URL] by access-group "nudo34-192-2" [0x7200cbe7, 0xc20d25c] Sep 9 13:48:57 [login to view URL] %ASA-4-106023: Deny tcp src nudo34-192:[login to view URL] dst nudo62-128:[login to view URL] by access-group "nudo34-192-2" [0x7200cbe7, 0x2cc4824f]