As of now as per your narration you are not fit for sports, we need to give sometime to get things correct. I think you shall consult a good Orthopedician( Specialist of Bone disorders) and you can even consult a good Homoeopathic Physician also, in Homoeopathy there are good medicines for correcting injuries, but avoid self consumption only a skilled Homoeo Doctor could help you.
Take all your reports to any doctor whom you are going to consult because medical history helps in making assessment of the status of health, unlike you have done here, where you have not mentioned which ligament, which injury
etc. etc. and no investigation reports.
You shall get your back and ligament corrected first and then flat feet management could be started.
Wish you a speedy recovery to health