Your scar is not yet fully mature. But, the direction being vertical is against the natural forehead lines. Scars cannot be made to disappear but can be improved by various techniques. Ultimately, you would benefit from a scar revision using Z-plasty techniques which would partly and optically convert the scar into a more natural horizontally leaning scar. Of course, with that surgery you would again need to undergo at least a full one year maturation process before it blends in. Obtain some consults a good luck.
Fillers and derma roller therapy by a doctor at 2 mm depth to obtain improvement in the depth and appearance of the scar...
From the photo it appears that the scar line is fairly deeply indented. This can happen when there was insufficient "eversion" during the suturing process. Unless you have experienced problems with wound healing in general, I would recommend to have a depressed scar like this narrowly excised and re-sutured. You should have face-to-face interviews with several surgeons before deciding.
I am sorry to hear about your accident. It looks as if the site healed well, but left a scar, which is what would be expected. At this point, the best option for you would be to have laser resurfacing (fractional co2 laser). I would seek a laser expert, who performs many of these treatments, as we do in our office. You may need a few treatments, but it should give a significant improvement. There are options for you, however, you just need to make a cosmetic consultation as your first step and find someone you feel comfortable with and trust. I wish you the best of luck, Dr. Emer.