From your description, it sounds like you have hormonally acne which naturally worsens nearer your menses, and during stressful periods. And as pointed out, changes in humidity play a big part too, so you tend to notice them after your holidays.
As for your treatment regimen, Differin works well on long-term acne control and reduces your blackheads and whiteheads (comedones). Larger bumps (angry red pimples) respond better to antimicrobial agents like clindoxyl, which contain benzoyl peroxide. Skin irritation may occur, so it is best to use them under a doctor’s advice after a formal consultation.
Lifestyle measures are also important in acne control, so do ensure you are aware of these.
- Cleanse, exfoliate and treat. Gently clean your face 2x a day, using a minimal touch technique. Don't overclean your face. (This is to remove all the old and dead skin that is clogging the pores, but not over irritating your skin.)
- Use oil-free or ‘non-comedogenic’ makeup products. Remember, you use makeup to look more beautiful, not to worsen your acne.
- Never ever squeeze a pimple and minimise touching your face. I know its easier said than done, but you risk scarring, darkening and spreading the pimple to other parts of your precious face.
- Wash your pillowcase, and your pillow on a regular basis. Your pillows otherwise collect all the sebum, makeup and dirt that contribute to pore clogging.