Did you actually get to your Dragonite? With Tyranitar's immunity and Mewtwo's resistance to psychic moves I would have guessed that you wouldn't.
If the issue is timing out then swap in some Gengars because you lack damage, and they offer more than Scizor and Dragonite.
If the issue is fainting before the timer runs out, dodge specials on your Pokemon that have higher DPS - the Mewtwo in this case.