Since you have already serviced the throttle body, here is quick turn job.
Remove the IACV and spray it with Nasa carb cleaner. There would be 2 holes, one with and one without a small criss cross grill. When you spray it, the balck stuff (carbon) start to drip out. Do it a couple times till the fluid dropping is not clean. Should take about 5 minutes. Then once cleaned, let it dry out for about 10-15minutes. Put it back in place and tighten the bolts.
You should be able to feel a difference. If not, then get the tappets adjusted. If it still doesnt work, there might be a problem with your Ecu not sending out signal to the engine, or it could be a problem in the distributor. Cant be anything else.
FYI, these things are not very costly, so don't drag yourself down to Honda. They will not only run up your bill, but will also ruin your car.
No offence to Honda or their engineers, but i personally dont have a good experience.
Lastly, when all fails, send me a PM. I will refer you to Maestro Tarik. He is well acquainted and fairly reasonable.