try using dial soap,it really helps..use over the counter medication and for dandruff wash your hair more regularly,this is more likely from not taking care of you're self,you need to exercise and bath more frequently.
wash your face at least once a day. two times tops (once in the morning, once at night) try not to touch your face to much because of all the oil on peoples hands and dont eat to much sugar.
And for dandruff, T-Gel or Head & Shoulders are good shampoos to use.
I don't have bad acne, but I visited my dermatologist and he prescribed something for my acne and it's working great. Maybe you could see a dermatologist?
There are many different types of acne medication. Start trying those and see which one works for you. Keep drinking a lot of water, too.