having a streak and then it gets really unfair

So I have been in diamond over 50% of my CC fights.
It just buggles my mind that everytime you get a streak you get into this party matchup that just seems unfair. I mean it's not closely matched at all it's just one sided.
I have managed to get to diamond 3 but not higher and I drop back to Dia 5 everytime I get there by very uneven matches.
I try to analyse my own gameplay and yes I do make mistakes and yes I do improve but it just seems strange that this is happening everytime.

It's probably because the system wants to put you at 50% win rate so it stacks team against you to bring your win rate back down. Most games do this.

Just play WHM and win anyway.

Just because you play WHM doesn't mean you win, you are just 1 out of 5 people.