Can I Restart Doxycycline For Chronic Cystic Acne, Including On My Scalp, Even Though It Recurs When I Stop?

Hello! I have a chronic cystic acne and I was taking doxycycline. However when I stop taking them, my acne reoccurs. I don t have any healthcare provider to talk with at the moment. So, can I take doxycycline again from the start? Aside from acne on my face, acne reoccurs on my scalp.