Hi there
Although antibiotics like doxycycline do work in the treatment of acne, using the same antibiotic for more than 3 months at a time on its own will lead to bacterial resistance and will therefore become ineffective.
I would suggest the following:
Cleanse and tone your skin with a mild frangrance and alcohol free solution such a
cetaphil.
Use a course of bactrim ( sulphur based antibiotic) for two weeks, if not allergic. I suggest this because you have already taken doxycycline. If you are allergic to Bactrim, try
tetralysal 150mg twice a day for up to 3 months and then stop.
You need to also use a topical retinoid such as epiduo.
I also suggest you try washing your face with
benzoyl peroxide ( benzac), this will reduce the oil build up. Some people do react to this by breaking out so do a test patch first.
Another option to consider is trying a
topical antibiotic with zinc, it's a good option if your acne is mild e.g. zinc and
erythromycin ( zineryt).
Do drink plenty of water and follow a healthy diet, low in sugar.
Hope this helps.