Here is a schmatic of a Vbe multiplier. This drawing is for illustrative purposes only!!! I have not prototyped and do not guarantee correct operation. I have not done a detailed analysis, but if you want to try it, I suggest you build it on a bread-board by itself, and try to set it up before incorporating it into your circuit. To set it up, turn VR1 to a maximum value, and VR2 to a minimum value. Connect two resistors, about 1k each, across the outputs labeled To N channel, To P channel. Set VR1 for 0V at the junction of the two 1k Resistors. Then set VR2 for ~4V across the resistors. If that works, you can add it to your amp, but turn VR2 back down, and then back up slowly in your circuit.
The component values for this circuit are calculated, and not necessarily 'standard' values. Use values as close as possible. This circuit is experimental, and won't give the best results, but will hopefully demonstrate the principles involved. It may requre additional emitter follower or source follower devices to be placed before the output drivers. Sorry, I do not have a chance to prototype this circuit. You'll just have to play around with it. Getting the driver to correctly output the signal efficently required complexity. It would be a good idea to simulate the ckt if possible.
If you choose not to use this, you may just lower the value of your 1.2k Ohm resistors in your original circuit.