Hi there, I suffer with it too
There’s different treatments available for it - soolantra as mentioned above is the newest one available and apparently very effective. Otherwise there’s azelaic acid in the form of finacea or skinoren - both prescription strength available from The Independent Pharmacy or Boots Online Acne clinic.
I would avoid acids until it is under control and concentrate on soothing and hydrating your skin. La Roche Posay is a fantastic brand for sensitive skin. Also Avene.
SPF wise, try Korean/Japanese SPFs they are a game changer. SPFs over here are sticky, greasy and heavy on the skin. Korean/Japanese are completely different - they’re like watery/gel beautiful textures that just sink into the skin leaving no residue.
Don’t know if you’ve heard of Dr Sam Bunting and Dr Dray but if not, search them on YouTube
Feel free to message me if you have any questions xxx