My Acne Medication isn’t working…

Patient: Hello, I am 18 and currently taking Tetralysal 300mg (Lymecycline) for my acne that i take once a day. I have been on these antibiotics for about a year and a half now, they were working but then my spots have started to come back. I went back to the doctors and told the doctor the problem, so he gave me a topical antibiotic solution (Dalacin Topical Solution, Clindamycin phosphate)to use once a day, he told me to carry on taking the tablets aswell. This topical solution doesn’t seem to working for me. Is there anything else that i can try???Thanks