the problem is not in the website / gmail BUT your computer. he has infected it with some keylogger or trojan so no matter even if you get a 'special email id' he'll still know it.
you need to disinfect your computer first.
then he won't be able to hack it anymore.
#1 : stop using internet explorer- its virus friendly,
start using firefox webbrowser.
#2: download spybot search and destroy - it scan and fix your PC (free and easy)
http://www.safer-networking.org/en/download/
#3 if that still doesn't work.
using Kaspersky Internet Security 2010.
download from here (size about 80 Mb.)
http://www.softpedia.com/get/Antivirus/Kaspersky-Internet-Security.shtml
install it , run full scan, it'll remove every sort of malicious program.(virus,trojan,spyware,adware,net… attacks)
& keep your laptop protected