Well, I am not sure this answer will help u, as the question is posed in 14. In order to help people resolve this question, I send some of my resolutions. Hope this will help.
if your shadowsocks is very slow,and this is not your net’s wrong. You can try the below tests to fast your ss.
1.change your ss server's config which is located in /etc/shadowsocks.json
--The port change to 443 will be helpful,as the default web service port is 443(i mean the website etc)