Sometimes it comes right at you, and sometimes when you least expect it.
As an educator, you need to deal with it now and then, because sometimes you just don't get the results you are looking for right at that time. It seems like you try and try, and nothing goes just the way you were looking for.
My advice is to just wait for it. Good things will come if you're persistent.
If you continuously role model incredible amounts of character and integrity when (notice I did not say "if") things go wrong to your students, then they will know how to handle it when things go wrong for them... whether it be in the classroom or not.
Recently, I, myself, had a major disappointment in my life, and believe me ... it stung.
However, I just kept going back in my mind to all of the good things that I have in my life... the hard work that I put in to get to that point. Interestingly, I wouldn't have been in that position to be disappointed unless I worked extremely hard to get to that point.
Your students are watching how you handle not only the good times, but also the times that things don't just go quite how you expected them to.
How are you going to handle the next disappointment? Are you going to wallow in your sorrows, or are you going to get back up, and show them what you're made of?
Remember, they're watching.