just take out /stop casting, i have the same macro without the stop casting and i have /use 13 and /use 14 in my macro also and it will use blood fury and my trinkets when they are avaliable and since they dont have a casting time or world cooldown then you start casting lightning bolt as soon as you hit the macro.

my macro looks like this:
/assist <name>
/cast Blood Fury
/use 13
/use 14
/cast Lightning Bolt