Breathe please. 
OSBot didn't hack you, you might've downloaded something else. 
  
If it took control of your screen, you have a RAT on your computer. 
You should try: 
Ctrl + Alt + Delete. 
Open up the task manager. 
Look for anything suspicious. 
Right click open file location and delete it from there. (Don't delete anything your computer needs or else you're fucked)