SSH Issue on new Instance

I have been logging into my new instance using SSH via putty(with puttyGen for the key). I get time-out errors. already activated ICMP and I can see it replying to me.

traced issue by checking vpc, subnet ,internet gateway and route table. everything seems to be ok.

ec2-18-176-118-154.ap-northeast-1.compute.amazonaws.com

Just started AWS and i'm quite clueless on how to proceed.