Clindamycin phosphate gel,1% for acne?

My doctor prescribed me Clindamycin phosphate gel,1% for my acne. I just tried it. Is it true that if you stop using this product when your acne is gone..it will come back twice as worst? Cause i don't want that to happen. And when you start using this gel will your acne get worst then it will get clear later on? Does this product work? How long do i have to put it on till i see results? I have pimples in between my eyebrows and cheeks. What happens if my acne clears up and then i stop putting on this gel? Will the acne come back?