Roles really don't give a huge advantage in CC. I've seen pure-DPS teams absolutely steamroll a balanced team and vice-versa. I've seen a team without a single DPS class win, and also get stomped.
It's entirely on the skills of the player.

I would suggest continuing to try, as that is the only way you will get better and see more positive results. Though you could be the best player in the game and still have RNG against you with who you're paired up against, especially in unranked. Best of luck!