Out of expectation

I really don't know how many times this happened. But today, it happened again. People should not put high expectation on something that they want, more directly is I want. I really cannot take the feelings of out of expectation, it totally pull me down into the valleys, as if I couldn't climb up anymore. Tears are flowing crazily, heart is aching so hard and my mind is totally disrupted.
I hate, I hate people who make a promise to me but they didn't meant it. And when they break their promises, they will give a lot of excuses, hoping that you'll be considerate and forgive them.
Seriously, I admit I'm not the considerate one. I try to be but I cannot.
Trying very hard not to upset by that but failed.
Trying not to think about it but failed.
Trying to concentrate on other things but failed.
Perhaps a good cry can wash away everything.