Answer:

First, since you have a significant level of combined chlorine (anything above 0.2 is significant), but you have a fairly high free chlorine level, I would recommend adding some non-chlorine shock to help oxidize the combined chlorine while not affecting the already high free chlorine level. Can you vaccuum off the dust on the bottom of the pool? If not, brush and then vaccuum to try to get rid of as much as possible. Backwash the filter once you have vaccuumed up the dust. Very few pool chemicals work instantly, so it will take some time for your actions to take affect. However, if the water is still cloudy after a couple of days you may consider adding a clarifier or phosphate remover, especially if the phosphate level is significantly high (you probably need to have this tested at a pool store).