WTF is up with that? I can't pick faster than about 120 in short spurts with my right hand (I'm right handed), but on the first try with my left hand I could tremolo pick effortlessly at over 180bpm (16ths). Sad thing is, I'm too old to learn how to play left handed, lol.
Go back to super-slow mode and work your way to it. If you can tremolo pick accurately and steadily before working towards it, most of the time you're probably tensing, which is a really bad habit.
Quote by Kevätuhri
Hail isn't too edgy for posts, posts are not edgy enough for Hail.

Quote by UseYourThumb
You win. I'm done here.
I agree with Hail.
If you can pick with your right hand you can pick with your left hand, and vice versa. Just takes a little time.