CPanel load balancing?

Hi all, We run a popular website - getting about 15 million peg views a month, about 5000 concurrent visitors at peak times. Our server seems to crash once every 5 weeks now - we think it"s when the server is under heavy load, and an update has gone wrong (but cPanel staff have checked this out and couldn"t find an issue). So we are thinking... maybe the server just cannot handle the traffic, 5k users at once, and daily process logs of 50% cpu and 50% memory usage. We use aws ec2 - a t2.2extralarge We would like to use aws elastic load balancing. Am I right in that I just duplicate our current whm server - and then keep it updated, like just keep both instances/servers up to date? Just needing a whm licence for each server? thanks for the help