Check out the tips in the "Some Q's about speed" thread in this section of the Forum. It's all good attitude/approach stuff. I have no way of knowing what you're doing that needs 'fixing', but try this.

Hold your pick at a bit of an angle, so that you STROKE the strings, instead of 'plucking' them. Try strumming chords like this:

On the downstroke, lead with your hand. Your knuckles should skim just above the strings, with the pick trailing along behind your hand. On the upstroke, your thumb should almost touch the strings as the pick follows.

Get a sense of the sound and feel this produces. Then pick single notes, teying to reproduce that feel. You will find that you're moving the pick up and down by rotating your forearm. It works.