Arny -
Ooooo Costa Rica - sounds fun! You're lucky!!!
I hope you clear up in time....just be patient (I know it's hard)!!
If Differin does not work by itself, you might want to ask your derm for a cream with Benzoyl Peroxide in it (Duac and Benza Clin are pretty much the same thing). I think using a topical under my makeup helps keep my pores from getting clogged up! Just a suggestion...I hope your regimen works for you in the long run!