Hate to lay a dose of reality on you, but no, you couldn't have kicked their asses, not unless they had no fighting skill and you were a good amount bigger. They would have kicked your ass.
Stop saying "Oh I knew I could have kicked their ass." You obviously know you couldn't have, hence why you felt so helpless and wouldn't risk it. There was two of them, and without some serious imbalance in strenght and skill and a bit of luck on your side, you'd have got your head kicked around.
You have taken a few MMA classes. You aren't suddenly a fighting god. Assuming you could beat up two other guys of around your age who for all you know could have trained even more than you is retarded.
You did the smart thing. You also did the ***** thing. Sometimes they happen eo be the same thing, in fact quite often. Deal with it and stop making excuses.