Sudden forehead cluster acne. To acne?

1. I had a mild acne problem (1 - 2 spots a month) since puberty 2. An year ago I started applying coconut oil as a moisturizer 3. Soon I got closed comedone all over my forehead which then spread to my upper cheeks 4. Then my entire forehead became covered with closed comedones 5. This stayed as is in the winters 6. In the summers, after some sun exposure, all my closed comedones started to disappear 7. And soon reappeared but this time they were bigger and in clusters 8. Within 2 days, both sides of my forehead and my temples were full of painful cystic acne that was spreading like a rash 9. The peculiarity was that the centre of my forehead and rest of my face was perfectly clear 10. Antibiotics controlled it but only to certs extent (tried azithral 250 for 7 days, clarothomycin 250 for 7 days twice a day and minocycline AD for 20 days) 11. Finally what worked was Isotretinoin 10 mg and it did well within 15 days. question is how to i get rid of clogged pores as they turn to acne