On acne medication that was working, and suddenly now having breakouts?

So I put Benzaclin on my face twice a day; once in the morning, once at night. I ve been on it for over 6 months, and it was incredible! Until recently.... It stopped most of my cystic acne, really only have maybe 2 in the time I was on the medication? I d have other ones here and there, but they were much smaller than usual and I didn t care much about them. Now, I m not sure which factor is causing my acne to flare up. The summer heat and humidity? My change in toothpaste? (I went from using Aim and Crest 3D White to using Cinnamon Close Up, which all have Sodium Laurel Sulfate, so would that even matter?) Or is it maybe that I ve been eating a bit more icecream than usual? I really just want my acne to stay far away. I don t know if it is any of the above things causing it. I ve been wondering if maybe it was even bug bites, but we do not have bed bugs and I know they are not from mosquitos... I m really careful not to put my cat against my face, and am always cleaning/sanatizing my hands and do not let myself or others touch my face. Pillow cases are cleaned on a regular basis. I just want to know how to stop the acne...