Replace the PCV valve.

The fuel filter is best replaced by an experience Honda Mechanic. It is a severe PITA and takes about 25 minutes for someone that KNOWS how to get at it and change it.

Change the air filter.

Fuel injector cleaner isn't going to instantly clean everything up and make it work like magic. It's gonna take 15,000 miles of using it every 3,000 miles to see a difference.

If it is leaking oil that bad, you need to fix that problem first and your problem should be about gone.