The best advice I have for you is to keep practicing everyday. Try to learn small sweep licks at a time, and start studying about arpeggios. I dont claim to be an expert sweep picker, but one tip is to use your left hand fingers very lightly. Just lightly touch the strings when you go to fret them. This has helped me. Palm muting may help you gain control as you drag the pick across the strings. I usually turn the gain down to about 1/2 to 3/4 power to help reduce unwanted noise. Hope this helps.