Hey – it happens to every DJ, unless you are cheating and using a pre-mixed CD for your entire set and miming your mix.
The best thing to do is not to beat yourself up too much about it, but rather sit down and write down what went well that evening (I was on time. I was prepared, etc) and what did not go well (equipment failure, poor transitions, etc) and jot down some concrete ideas on actions you can take to make things better.
Also, if you can get constructive feedback from someone at the gig, or have them listen to your mix if you recorded it, and see if they notice anything amiss. Often times what sounds as a screw-up to the DJ really isn’t noticed by people on the dancefloor.
Hope this helps!
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