Acne, pimples, bad skin for over a decade. Now reduced, manageable pimples for over two years strong.
Even if this doesnt help your acne/pimples/skin situation, this has helped me in other ways, in a general way, and may help you in a general way, as well.
(Also, Im not sure about the difference between acne and pimples but Im almost certain Ive had both.)
I cut out entirely:
fast food
donuts, chocolate, cakes, sweets, ice cream, bags of chips (not the hot chips, I still eat them), biscuits, liquorice
Tomatoes (because they make me break out, must be the acid), mustard
Tomato sauce, mayonnaise
Apples, oranges, bananas, and so on
Fruit juice, soda, tea, coffee, milkshakes
I basically only drink water and full cream milk and (small, recommended amount of apple cider vinegar in the morning).
I also cut out sugar, that was the big change of my diet. I didnt cut it entirely. I cant avoid sugar in everything because a minimal amount of sugar is in everything. For example, I drink full cream milk which has sugar in it, I use spreads that have sugar in them, (although I avoid the higher-sugar spreads such as honey and jam). I noticed that cutting out sugar has improved my mental state, I feel better, I think clearer and it reduced headaches.
I also stopped touching my face! That was a big one. It was tough but now I basically never do it. Strong, noticeable difference. Also, I never pop pimples. I dont let tissues on my face for too long nor too rough. It helped.
I dont wash my face or use creams or anything, barely ever did, but tried some briefly back when I was trying to help my acne. I only let the water in the shower briefly touch my face. I also only shower once every second day, so one day shower, the next dont shower. I used to shower every day but I found it made my skin suffer.
I started drinking more water. I now drink a full glass of water once every hour until evening. When evening comes and dinner is over, I stop and only drink a little bit as recommended.
Drinking more water not only helped my skin but helped in every way. For instance, I think clearer and dont get headaches as much.
I still drink full cream milk, still eat cheese, so I still intake dairy.
I stopped drinking milk for a few years, but looking back, it was in that time that I had the worse acne.
I am not vegetarian or vegan, I eat meat and have a pretty standard diet. I still like pizza, hamburgers, hot chips, meat pies, sausage rolls, lasagne, and so on, but not the ones at fast food outlets.
I also avoid eating at places that are untrustworthy and only eat at reputable restaurants if I have to eat other than my own food.
I still get a small amount of pimples still. But, for a good couple of years or more, it's very manageable, compared to before. Beforehand, it was much worse for a long period of time - ten plus years.