Don't worry, I'm in the same exact boat as you. When I first started Retin-A about 2 weeks ago, my skin was clearing, but towards the beginning of the second week I broke out with the whitheads and everything. I'm sure this is only an initial breakout because It's going away.
Initial break out's go away pretty quick in most cases it'll take about a week to start going away. There's only one intial break out (keyword is INITIAL, meaning beginning, not reocurring). Give it some time, Like the instructions say: "RESULTS CAN BE NOTICED AS EARLY AS 2 WEEKS, BUT 7 WEEKS IS NEEDED FOR FULL THERAPUTIC RESULTS, YOUR ACNE MIGHT GET WORSE BEFORE IT GETS BETTER"
My advice is to stick with it like I am.