Earlier in my career, I had a boss who promised me a pretty major promotion. He assured me that he could make it happen and that while processing would take a few weeks, the job was mine.

That turned out not to be true for a variety of reasons. A few weeks later, not only was I not promoted, he was no longer with the company.

It was a bitter blow that left me upset, doubting my future with the company I then worked for, and not sure what to do next. My immediate response was less than helpful. I still performed well at work but was generally sullen and withdrawn.

I had no interest in proving myself again to a new boss who seemed a whole lot less enamored with me than my previous one was. It was a rough time, but one that, in retrospect, I could have handled better.

Here's a look at what you should do after a career setback.

A woman at a laptop puts her hand on her head.

Don't let a work setback define you. Image source: Getty Images.

1. Don't get hung up on it

It's reasonable to be upset when you are dealt a career setback. In my case, I had lost a significant raise, better benefits, and a major jump in prestige. Being angry or sad made sense, but letting it take me out of the fight did not.

The correct response would have been to vent my anger in private and get back to it at work. In my case, it's not that I stopped performing my job well, it's that I stopped doing all the little extras that had gotten the attention of my first boss.

2. Do an honest evaluation

Sometimes not getting a promotion or being passed over in some other way hurts, but it's not a statement on your future with the company. In my case, my association with the previous boss marked me to some of the people who had decided on his removal. I had enough support from lower-level bosses to not get fired, but my chances of moving up were very small.

Once I came out of my funk, I was able to honestly say that my chances of being considered for a promotion where I worked were nonexistent. Because of that, I began looking elsewhere within the company and externally.

3. Execute a plan

In my case, my plan involved aggressively trying to leave the team I was on, whether it was for another job at that very large company or to go elsewhere. For many people, a career setback can be a lesson -- an opportunity to make some changes in order to not have the same disappointment happen again.

If appropriate, talk to your boss about why you were passed over and what you can work on. Make a plan to improve and to be ready for the next opportunity. Focus on progressing forward, and past setbacks will diminish in the rearview.

Don't let it break you down

For too many months, I focused on what I lost, not what I had. I liked the job I was in, but not getting promoted sapped the joy from my day-to-day existence.

That was a mistake. Yes, I had been dealt a setback, but it did not change the fact that my situation was a good one. I worked with people I liked, and while the big boss no longer had my back, lots of other people did.

When something bad happens, process it, then get back up and start the fight anew. It may not be easy, but there's nothing to be gained by wallowing in self-pity.