Im 10 st 4ibs .im 14 and 5 ft 8 in..i work out and eat healthy but no matter what i cant lose wieght or tone .?

am i overwieght ??..how can i tone my body quickly to keep up motvation and i only have the summer to really put lots of time into this...please help me....the info on the net is really contradicting ...thankyou xxxxx