Have you ever tried a skin roller? The idea behind them is that they prick tiny enough holes in your skin that it doesn't cause any damage, but still gets your skin to start regenerating themselves. It helped with a lot of my scars.
Otherwise you want to use healing skincare (always focus on the word healing), for example sea buckthorn oil or tamanu oil.
Some cosmetic products can worsen acne and increase the risk of scarring. Choose non-toxic cosmetics and apply them sparingly. Use paraben-free skincare. Parabens are preservatives used in many cosmetic products. They can cause skin irritation and inflammation for people who suffer from acne, and may be a potential allergen. Butyl and propyl paraben are more toxic than methylparaben and ethylparaben. But, the latter is more easily absorbed by the human body.