From what you've described, this is what I think you're wiring should look like. Keep in mind, this is just a guess. I can't see what's going on, and I'm an internet away, so I can't touch/measure/test anything.

The wiring diagram for the switch, can be found in the installation instructions.

If you provide images, and/or a better description of what wires and cables are in each box. I'll be able to provide a better guess, as to how this should be wired.

NOTE:

The diagram is based on your description, and is my best guess as to what your wiring looks like. If you're not sure what to do, or feel like this project is over your head. Do not hesitate to contact a local licensed Electrician.

No way from here to know which wire fed the light or fan, but you have a continuous hot feed into the box that fed the receptacle, light and fan. The third wire, maybe it fed the fan or maybe something something else farther down the line, if the latter that needs to be tied in 100 percent to the hot feed. All whites still tied together, blacks to the dimmer from the light and hot. All grounds tied together set with a screw to the metal box. Securing the ground to the box is not needed if the box is plastic.

Before I got too wordy, here is a sketch

Still have to learn to format better

The sketch is a little rough, it should get the idea across I hope