Hi, Riya. People that are acne-prone can have "quiet periods" and flare-ups. Thus, even if your acne is cleared you need to keep on maintenance treatment for the long term.
It seems that Retin A helped you keep your acne at bay. If you flared up again you need to restart treatment. In addition to the right daily routine (cleanser, oil-free moisturizers, etc.) you may need to consider the MDacne Retinol 0.5% which is similar to Retin-a and can be purchased now over the counter without a prescription. 🙂
Shop Retinol 0.5%/ Niacinamide 4% cream