Hearthpwn

1. Understand that this game is hugely RNG.
2. There's only so many cards in a deck, so answers will pop up frequently to what you just played.
3. Yes I know you stated that you don't like "It's just a game" excuse.  But reguardless, it is a game, and if you are getting that frustrated, you should really take a break till you calm down. 
4. Games are meant to be fun and a pass time. If you can't take quite a few bad beats in a game, especially one that has such a small pool to draw resources from, than you need to find another aspect other than ladder climbing.
5. My final point here. The only way to deal with the rage that you are dealing with, is to figure out exactly what it is that's making you angry, and learn to deal with it.  Each person is different and different things will make others upset.  Each situation is unique.  You have to learn how to deal with that yourself, and get passed it.  If you don't, the longer you play mad, the worse your games are going to get, and the more mistakes you will make.