Stage fright, yeah.
I'm so damn agiated if I play in front people, it's not nice anymore. And there seems nothing I can do about it.
So, what to do against it?

>>1
Don't play in front of people.

Relax and remember why you started performing in front of people in the first place. Maybe you need to take a break.

Did anything change, that you can think of?

It's better if you're playing in a larger group. If you're in a band with enough people, you can convince yourself that no one is looking at you and that they won't notice if you screw up. Unless you're a lead singer or something, in which case the whole point is to get them to notice you.

In my own experience, stage fright usually came down to worrying about whether I'd make a mistake, or too many mistakes, or be really obvious about my mistakes, etc. So the only other thing I could offer is to say that most people don't care that much about the mistakes, and unless they're musicians themselves they rarely even notice. In general I find musicians spend so much time trying to improve on their skills, and thinking about whether they did it "right" or not, that they don't realize how little most audiences actually notice.