That's a little far isn't it? Killing yourself?
There is ALWAYS a way to get your account back regardless if he changed the email or not, simply open a support ticket on the Steam website. They will ask you to provide proof, simply give them your credit card CCV number or something or even a CD key you activated on Steam.
If you tell me you can't do this it's clear you:
a. Haven't tried or
b. Are coming out with complete shit.
Good luck.