Here you are describing 2 problems, 1) pimples
on face and red spots 2) pain inside skin below the feet. 3) weakness in body.
For problem one that is pimples, the cause it seems at your age to be hormonal
imbalance complicated with secondary bacterial infection (if there is discharge of pus from the pimples)
and for pain below feet (while walking) may be because of weakness and improper nutritional diet.
You should start having healthy diet. Consisting of balanced meals with lots of green leafy vegetables and fruits. You should check your haemoglobin
and vit. b12 levels in your blood. Start constitutional homeopathic
treatment by medically qualified homeopath for treatment of pimples and red spots for permanent cure.
thanks and regards
Dr. Kartik Aswani