I've struggled with cystic acne for about 3 years, in the second year which was last year i decided to visit a private dermatologist as I was recommended one by my cousin who also sorted out her acne. Before going to the dermatologist I had been on countless treatments both over the counter and prescribed by my GP (duac gel and differin are the ones I remember being prescribed but I've also been prescribed others containing benzoyl peroxide and over the counter treatments include sudocrem, basically every spot treatment out there, tea tree oil, black African soap, coconut oil.) I also stopped consuming dairy which made no difference but now I just don't drink cows milk and have replaced it with soya milk. Visiting the dermatologist was my last resort basically and he prescribed me accutane straight away, I went on a 10mg day dose over the course of 8 months with minigeste birth control which I carried on taking for 2-3 moths after I had finished the accutane because I still had some left. So I was completely acne and scar free after my accutane treatment for about 4 months then in summer I started getting minor breakouts again but I thought it was just because of the sun. My skin was still clear overall but breakouts were still coming so I bought a bioderma moisturiser which cleared the spots but they came back yet again and this time they were cystic just like before so I went to the GP and was prescribed limecycline pills once a day and differin cream once a day too, I went on it for 3 months and only saw improvements in the last month but during this time I had also been drinking fennel tea so I'm not sure what helped. I then switched from my bioderma moisturiser to aveeno moisturiser and started using Indian Aztec clay mask twice a week which further helped to clear my skin but now everything has stopped working and I don't know why. I even took probiotics for about a month & no improvements. I've had blood tests to test or my hormones but everything is fine, drink water, eat healthily and clean my skin twice a day but the cystic acne won't stop coming and I'm even considering accutane again but this time, higher dose. The areas i get acne are n my nose, on the pores on both sides of my nose, my chin, my upper lip but now I'm also starting to get them on the sides my face and my cheeks
I believe although you took accutane for 8 months the dose of 10mg was too low to permanently stop the acne. It is common for some people to relapse with their acne and is why sometimes a dermatologist will recommend you to use a retinoid cream such as epiduo to prevent the formation of acne again once you have stopped taking accutane. I think you should go back to your dermatologist and ask to receive a second round of accutane but this time using a much higher dose of around 1mg per kg of body weight each day in order to really attack your acne, and should hopefully not require 8 months but only 4-6. Also ask for a retinoid cream after you finish accutane just in case it comes back again.
Don't waste time taking pointless antibiotics and using face masks and all these products that do nothing for skin. Definitely completely remove dairy and milk from your diet and maybe try almond milk instead of soya as some people also break out when using soya milk instead of cows milk. Be sure to eat loads of fruits and vegetables each day but don't make it something you force yourself to do, drink 4 or more liters of water a day and do cardiovascular activity. This will be good with the accutane and post accutane and should see the best results for you. Good luck hope this helps!