If I used my PWM output to create the 'average voltage' using the duty cycle. This signal then into a DAC and then into an Op-Amp?
While it will have an average voltage determined by the duty cycle this will have no effect on the peak voltage and so will not affect anything.
This is an X-Y problem, why do you want the waveform you claim and what impedance does it have to be? that means what current are you expecting this signal to drive?
This will create my AC signal matching what I need in the first post?
To create an AC signal you will need to have a split supply to drive the op amps. That is one with a +12 ground and -12 V output.