I'm very sorry to hear about Rex. No, it doesn't make you a bad owner; whether you cry or not is no sign of how much you care about your pets. This is a terrible tragedy.
I hope I'm not being insensitive, but may I suggest that you wait a while, and then get another snake? This is a classic piece of advice dished out for the owners of dogs, cats, everything, and I don't see why it shouldn't apply to snakes. The usual reaction will be for you to say "No, no other snake could ever replace Rex." That of course is perfectly natural and indeed true, but it would still be good for you to share your love with another snake after a while, in honour of your passed away companion.
I'll say it again: I am very sorry to hear this terrible piece of news, but not half as sorry as I expect you are. Ther best of luck to you.