Ouch.

Well, now that you've lost your CV assets, you're offensive capablity is going to be reduced tremendously. The question is, how badly damaged are his CV's? If both American CV's took at least a couple bombs or torps, then they may be damaged enough to keep them in Brisbane for awhile.
Your one ace in the hole is knowing that if he has fortified Lunga with troops from Nomea, then that means that Nomea, Port Efate and Luganville are either very lightly defended, or totally undefended. Same goes for Gili-Gili. If he sent Australian troops to Gili-Gili, then Port Moresby is not heavily defended. The Allies simply don't have the troops at the beginning of scenario 17 to cover all the bases. And you will be receiving the 2nd and 38th divisions within a month.
If his CV's are still operational, and yours aren't, then I'm afraid that you're pretty much already on the defensive, unless you can find a way to use your surface forces to your advantage.
If I were you, I'd concede the defeat and beg to start over, this time playing scenario 19 with Japanese ship commitment set to at least 140% and Allied to 100%.
Or you can just wait to finish our Coral Sea scenario, and you and I can start a scenario 19.
