Slow wipers

Got a wee issue with the car I'm needing some help with.

basically, windscreen was a bit dirty so put the washers on, the wipers went to the top of the screen (vertical) and wouldn't go back to their rest position no matter what I did, turned car off then back on, still not moving, messed about with the stalk and they started working again, only now they are really slow, intermittent they take ages to move, normal constant speed is really slow and the fastest setting is now slower than what normal used to be, the wipers also now park about 2-3 inches further up the screen than they used to.

any ideas what's wrong?