Thanks for writing
After reading your problem I understood that Your body weight is falling on joints and causing pain and hurts while walking so first reduce your body weight by taking good diet and avoiding fry items,junk foods,and have a balanced diet which contains 40% of carbs,30% of proteins
and 10% fiber...You had not mentioned your height and any health problems your are having before or undergone with any medications....... And coming to your age factor you need lots of calcium so take milk,soya,tofu,curd in your diet to have adequate calcium to your body
Once get checked with your BMI and start having a proper diet with 5 to 6 meals a day...
For further query write me back