There's nothing wrong with nervousness or any other emotion, and you really shouldn't try to avoid or numb motional responses, even if they are so strong that they prevent you from functioning. Instead you need to change your mindset about emotions. Having a negative mindset about negative emotions is what hurts you, not the emotions themselves. Thinking "I shouldn't be nervous/unhappy/etc. because a DJ is never nervous/unhappy/whatever!" hurts you because you tie your self-worth to this idea of being a Don Juan who doesn't feel those emotions that it's impossible for a healthy person not to feel. Then, you fail to live up to your idealised self, and that leads to a spiral of hurt self-esteem and the descent to depression, especially if you have narcissistic tendencies. I used to have these episodes regularly and it's only by changing my mindset about things and re-integrating the various aspects of my personality that I've gotten past them. Not everyone will be able to relate, but if you can, take a look at
Dabrowski's theory of positive disintegration.
The mindset I've developed about emotions is that emotions are one of two things: (1) a message from your sub-conscious, or (2) a tool, a way of motivating yourself or altering your psyche in a useful and temporary way.
1. Emotions as messages. Your brain is constantly and sub-consciously processing everything in the environment and to do that quickly it has to sacrifice accuracy. The conscious part of the brain is more accurate but slower, so when the sub-conscious thinks it has something important, it sends a message in the form of an emotion to the conscious brain for re-assessment. Your job, as the conscious, is to perform this re-assessment. There's an article in (I think) the DJ Bible which mentions assessing your feelings instead of following them blindly or suppressing them altogether.
2. Emotions as tools. I've noticed that I'm at my most productive when I'm angry and I've realised that there are two reasons for this: one is that anger increases
psychological arousal and motivation, and another is that I am trying to displace or take my mind off of my anger by doing something else. I've also learned that I can make myself more or less angry, so if I really want to get shit done, I get angry. If I wanted to beat someone up for money, I'd make myself angry at them.
Sometimes strong emotions can be unpleasant but you have to learn to endure them. The best way to learn this is to read Stoic philosophy, like the Enchiridion of Epictetus or the Meditations of Marcus Aurelius. Epicurean philosophy has some good things to say but the Epicurean's overall aim is the avoidance, rather than the endurance, of emotional pain, which is wrong - you can only avoid for so long, but endurance is forever.
These days, I enjoy strong emotions, sometimes even sadness. All this is mindset.
Mindset is everything.