I'm stuck at guitar. Can you help?

u gotta practice your scales and arpeggios. the reason ur having trouble playing fast is because your left and rite hands are not in sync with eachother. once thats taken care of, it really just becomes a matter of getting comfortable with what your trying to play. because unless theres a physically taxing quality to it, like a very wide stretch for instance...it just boils down to picking the same way you did to play those scales. and the scales are the simplest way to address that problem.