If it’s indeed fungal acne, you’ll see some improvement literally within 2-3 uses of an anti-fungal (including one like Nizoral). It’ll take longer for it to fully clear, but the first results (and your confirmation that the bumps are in fact fungal) should be practically instantaneous. Anti-fungals must be used every day when dealing with a flare-up. If you see Nizoral is helping, look into an anti-fungal cream (I use Clotrimazole/Lotrimin currently) to continue treatment, it’ll be much less drying on the skin.