Guitarist needs help

I've been playing the guitar for about 5-6 years now. I'm pretty good, I play a death metal/thrash/prog metal style. I'm practicing on how to sweep and it's kicking my ass. Any pointers?

its fairly easy, the only hard part is being patient. it takes ALOT of practice, just go on youtube and look up basic sweep picking patterns, start slow and dont get ahead of yourself, if your trying to go faster then you can you wont learn, just get the hang of the motion before you slow progress to a nice speed. and practice practice practice.