there are two different problems you are having
first is heel pain which is due to long standing and hard shoes
another problem is both legs heaviness and paining which is due to spine problem
Next Steps
for heel pain
any pain killer with serratiopeptidase combination
antacids
for 10 min put your heels in hot and cold water alternatively twice a day
Go to physiotherapy and get
PARAFFIN WAX BATH
PLANTAR FASCIA STRECHING EXERCISE
if pain not relieved in 15 days go to spine surgeon for examination