Part of not needing better gear does boil down to getting your rotation right and using your taunts effectively. For some of us it was really simply to learn these things but for others it may take more time.. (Do you automatically understand you need a clearn UI and no delay keybinds for taunts?) Not likely do you understand this and it will take time.. Delay = Threat lost
So I looked you up and you pretty much have Expertise capped right now. You need to start getting away from that hit and exp gear into gear with avoidance / mitigation stats on it but if you are already having threat problems it just comes down to practice..