Just missed grad school application deadline..what can I do?
I just missed the my grad school application deadline....... This is the biggest and most serious mistake I even made in my life...


If that's really true, then what a great life you've had.  You'll bounce back from this and be back to sunshine and roses sooner or later.


  [D]oes anyone of you know if the department would accept my late application in this instance? 


Of course not [i.e., we don't know], because you haven't told us what department you've applied to. 


  Is there anything else I can do?  I am even too shamed to contact my prospective advisor regarding this situation.


Taking you at your word, letting shame prevent you from talking to your prospective advisor is the biggest and most serious mistake you've ever made in your life.  Don't do that.  Talk to your prospective advisor as soon as possible.  (There is no need to write about it in a panicked or alarmed tone.  If this really all just happened in the last two hours, it is quite likely that you'll hear from the admissions personnel as well.  But calmly informing your prospective advisor of the situation will be helpful.  If she tells the department that it was not your fault that your application was not submitted on time, it can only help your case.)  If it's very soon, there's at least a reasonable shot that this can be straightened out.  The worst case scenario is that you may have to apply elsewhere or up to one year later.  This is suboptimal and you should do what you can to avoid it, but it would not ruin your life.  Really.