Thanks for your query,based on the facts that you have posted it appears that you have lump in left groin which increases in size on standing and hurts on lifting weight.
This is definitely Lt Inguinal Hernia
and the lump that you feel is content of the sac either omentum or intestine .
Please note that hernia can not be cured with medicine ,Surgery is the only treatment option for inguinal hernia.
Please consult qualified general surgeon
for examination and get operated at earliest..