I'm terribly sorry for your loss. Here's a site which deals entirely with pet loss. I know many people who have found the information here to be very helpful in dealing with their loss: http://www.petloss.com
Hwangster, sorry I didn't learn about Mentos until now. He was a great cat and you are his great forever friend. It is a great boon to be there for your friends in death as well as in life, though a terrible passage it may be. And as there are such things, although they may be beyond our seeing, I'm sure that flights of angels did sing him to his rest.
Sorry I'm a bit dizzy right now, but you take care and may you be strong on the road of grieving.