Google 'vegan induced acne' it exists.

Going vegan on its own totally won't help your acne - it really depends what you ARE eating, rather than what you aren't (to an extent).

I have also experienced huge acne breakouts from focusing on 'a vegan diet' in the past - i.e. focusing on cutting stuff out and only really adding in nuts in huge quantities, which are packed with omega 6 (highly inflammatory if not balanced out with omega 3). I even ate more empty foods, because I wasn't sure what to eat as vegan, so had lots of pasta and bread. I remember eating a dinner regularly that was essentially just mixed beans with dressing! I also didn't eat enough calories, as I was too busy thinking about what I SHOULDN'T eat! Most of the foods I ate were inflammatory (high GI or high Omega 6).

Recently, I went 'accidentally' vegan most of the time purely through adding in plant-based foods that were nourishing and good for my skin, and not focusing so much on cutting too much out (except refined goods & dairy - I have never eaten meat) and have had huge success. I found that I stopped bothering to eat fish and eggs, since they didn't 'help' my skin personally and loaded up on beans and legumes for protein. I have barely eaten any gluten - mostly because I don't find wholewheat bread particularly nourishing, nor huge amounts of brown rice. I have loaded up on colourful veg, green and berries instead and now have glowing skin, which is also super fast healing, despite quitting the pill recently (see my recent post). When choosing what to eat I now think about what will make me feel great, give me tons of nutrition, and eat that! I try to have protein with every meal (even breakfast; I put almond butter in my porridge), have anti-inflammatory drinks throughout the day (lemon & fresh ginger, matcha green), raw carrot, avocado, a range of colourful veg and steamed greens. I never have blood-sugar drops any more or crave junk food.

Maybe focus on clean eating, rather than any one 'type' of diet and see how you go.