Impressive, your acne scars have reduced to a state where as
sensitive sapphire has suggested; micro-needling would be of monumental benefit to you, looking at the depth of scarring & amount of it I would recommend you use a pen at a 1.5mm needle length.
For faster results (less months waiting for it to go), you can go as high as 2.0mm, please do ensure that it is a micro-needling pen as this would be the best tool in this case. And if you do end up doing micro-needling, it is best to buy the tools and do it at home, going to a clinic is a waste of money nowadays.
Subcisions are an excellent choice, however filler is short lived, pointless, and a waste of money. I would also recommend having a look into Co2 Laser Resurfacing, as the amount of scarring it can reduce after adequate sessions are in the 90% range, which is all backed by verified clinical studies.