Thanks for aksing the query,
Doxycycline is the drug given in periodontistis, i would advise you not to take any drug by your own.
I would advise you to visit to the Dentist
get the checkup done,take an OPG radiograph.
Go for complete mouth scaling, polishing and curettage.
Take lukewarm saline rinses and antiseptic mouthwash rinses.
Take the drugs under the prescription of your Dentist.
Maintain a good oral hygiene
Hope this helps out,