If I made a mistake at work and I am pretty guilty as nobody said Nothing at all neither insult nor say that it was just a mistake and its ok which is making me feel even guilty so what to do?

You have to correct your mistake. If it was something illegal, go to a manager there you trust and explain what you did. Explain how you feel about it and what you will do to make it right. Be prepared if it was something illegal for there to be other consequences though.

Just do what you can to make it right. Once you have done that, put down the guilt. Move beyond it. It was a mistake and you learned what not to do the next time it comes up.

A mistake is only truly a mistake if you learn nothing from it.