CE-CE-Class AB Amp Design Help
The main error is that R6 (the load) should not go to ground - it should go to +9v to provide bias to the output transistors.

Also R8 is much too low a value - it needs to be approximately Hfe*R9. Maybe 100k.

The bias on the driver stage stage, Q3, is not well set - it will depend upon the Hfe of Q3.  Ideally with no signal the collector of Q3 should be at about half the rail voltage. 4.5V in this case. An emitter resistor and a resistor from base to ground can stabilize the operating point or even better is to have another stage with DC feedback.

The load is returned to the positive supply to provide what's called "Bootstrapping".  Without that the base current of Q5 would cause a voltage drop across R9 and limit the positive excursion.  The current into Q4 is provided by Q3 and is not so limited.

Here is an example Class B audio amplifier with those changes. This one uses diodes instead of the diode-connected transistors Q6 and Q7.