This may be due to calcuim deficiency which leads to muscle pain and can be treated using
calcium supplements
Try going to serum calcuim and
electrolytes once
And when there is pain and tenderness in calf muscles try a bag of hot water it helps relief pain and drink a glass full of milk as u are still young and try some outdoor activities to keep urself fit
Next Steps
Calcuim supplements
Calcium rich foods like egg milk etc
Health Tips
Take plenty of water and milk greens eggs and fish if u are a non-vegetarian