You need to consult nearest vascular surgeon or at least surgeon to rule out peripheral vascular disease...Consult them they will do the needful.

Hello there. It could be due to some disease affecting your blood vessels in your lower limb. And since you said that yours is a job which requires you to be sedentary and you are overweight also, therefore peripheral vascular disease is the first thing that should be ruled out. Get a Doppler scan done and consult a surgeon. Regards