The sad reality here is that you're a marked man. Or woman. The system has been watching your Arena performance for an unrevealed length of time and now adjusts your personal and team ratings accordingly. In many cases, that's downwards. There's no way to get a fresh start, even with new teammates, because the system has tracked your 'skill', which apparently is nothing more than your win-loss record. The only way out of this slump is to keep winning, according to Slorkuz. The idea is that your hidden, personal, and team ratings all have to converge before it starts moving towards a (hopefully) better direction.
I understand the system the way it's explained. It makes sense. What doesn't make sense is how the system was unleashed to the community without a proper introduction. Or why. Breaking in a new system while a season is already underway is insanely bad. I mean, the official calculator on WoW Armory doesn't even reflect the announcement that teams below 1500 earn the same as a 1500 rated team. A detailed explanation would've been welcome, specially for changes of this magnitude. Their slew of blue posts revealing everything piecemeal is just a horrible way to go about it. In fact, it feels like Blizzard is deliberately keeping everything mysterious because they're still tweaking the system.
It's no fun for anyone to win and end up with a losing record. A win is a win. In the NBA, for example, if the Lakers win against the top-seeded Celtics, it's chalked up as a W right up there when the Lakers beat the lowly Clippers. It's the same thing. In what twisted universe does winning games result in getting lower ratings? It might make sense technically, Gaussian Density Filter and all that, but on a human level, as a player, it's just no fun.
You would think that Blizzard, in their great experience and success with game design, would be aware of this. If anything, it seems like the new system has become even more prohibitive and unenjoyable to a larger player base. If their aim was to make Arenas more enjoyable to more players, a lot of feedback from players tells me that they might have missed their mark.