Read about a proxy variable in a .npmrc file but it does not work. Trying to avoid manually downloading all require packages and installing.
Just open the new terminal and type npm config edit and npm config -g edit. Reset to defaults. After that close terminal, open the new one and type npm --without-ssl --insecure --proxy http://username:password@proxy:8080 install if you need globally just add -g.
It worked for me, hope it`ll work for you :)