I guess I'll just make this short since Keith covered it. I don't know what its going to take for you to understand this but perhaps reading the same articles about it over and over again will help:

Bankroll Management.

Your edge in the game can be huge, but without a proper roll, you're destined to lose. If you can't get your head around this, you need to study this more, read about variance etc, understand why you shouldn't play underrolled. And lastly, find out what feelings or events drove you to play above your head and work on them.

Please turn things around, we want to see you succeed. Bankroll Management is the only answer. Good luck.