To be honest, although your score wasn't excellent, it also isn't too bad and there is still a lot you can do.
The best way forward is to put that behind you now, there is nothing you can do to change that, but you can take another course and go a different route to obtain the qualifications that you need for your chosen career.
I take it you are in graduation year now? That is a whole new chance to try again. If you can get good results here, it won't matter what happened in 12th.
I know it is hard when you know you could have done better, but learn from that, study hard for the next one, and take comfort in the fact that it actually wasn't a terrible score.
Good luck for your future, I'm sure it will be bright!