wordpress - ELB HTTPS doesn't work -

i have 2 webservers(ec2 instance) in cluster , 1 load balancer ssl_certification.i want deploy wordpress service(lamp) in webservers. these configurations: 1-elb:

listener: load balancer port:443 instance port:80

security group: port range:443

2-webserver:

security group: port range:80 source:elb security group.

3-/etc/apache2/sites-available/example.com.conf

 </directory>   <virtualhost *:80>            servername ${instance_address}            serveralias www.${instance_address}            serveradmin webmaster@localhost            documentroot /var/www/html/${instance_address}/public_html                 errorlog /var/www/html/${instance_address}/logs/error.log            customlog /var/www/html/${instance_address}/logs/access.log combined       </virtualhost>

my elb(with https) doesn't work or slow. have change , edit file: /etc/apache2/sites-available/example.com.conf