Do I stand a chance in US universities? How can I ask for so many recommendation letters?
Also, seeing that I did bad in plenty of my courses, would it be okay to ask for a recommendation letter from a professor whom I did bad in his course?


It is generally not a good idea! What do you expect the professor to write if he only knows you through a course that you failed? Best case scenario: he tells you honestly that he can not write a strong letter for you. But he may also write a bad letter, which would seriously compromise your application.


  keep in mind that I might apply to about 15 or 20 universities, that's a total of 60 letters ! How can I pull this off?


You would of course send the same set of 2-3 recommendation letters for all your applications.