I guess this means you trinketed the first stun? without their cooldowns up?? If so, thats a big mistake, and your partner should peel for you in this instance?
Also what comp are you playing? that matters as different comps will use trinkets at different times due to the types of cooldowns available be them offensive or defensive.
Dropping to 20% hp in a stun is fine if you dont have to waste a major cd to live through it, you just have to trust in your partner to peel/heal etc. This will allow you to save those precious cds for when you do get stunned during reck/bs and wings. Not saving them is death and it bloody well should be because you were not skillful enough to recognize this fact or see it coming.
Im not having a go or flaming at all mate, just keep at it and try to apply some of the above and you will progress as a player and become better.
Don't run to the forums and cry nerf, the best pvp'rs look at what happen'd and think, "why did that happen, and how can i stop it from happening again" or "what did i do wrong there that allowed that window of opportunity for my enemy's to capitalize and how can i prevent that next time.
Don't get bitter get better