How many interviews I had, we had, you had is irrelevant. What's relevant is that you get what you're going to these interviews for, no matter how many attempts it takes. Everyone gets different amounts of luck meaning that some get a job straight away and others don't. Anyone who is boasting about "I got a job first interview, my interview skills are amazing" just applied for the right role at the right time and didn't have to go through all the **** others go through.
The fact is that there are people out there that will submit hundreds, if not thousands, of applications, and from them they'll get about 3 interviews, all of which will be unsuccessful. You are young and have been invited to 6 interviews, meaning you have the necessary skills for employers to look at your CV and like the sound of you. One of them is going to look at you in person and like the look of you as well. Being invited to 6 interviews is, in fact, quite the achievement in itself. DO NOT GIVE UP.
How good are these jobs you wanted? Because for all we know, the reason you're getting rejected from interviews for jobs you like the sound of could be because something even better is around the corner. That's how you have to think about it.
Don't worry about us or your peers, just focus on getting what you're looking for. Good luck.