Thank you for your query at DoctorSpring.com
I understand your concern.
The kind of pain you described is definitely muscular in origin and seems to have started because of your low periods of standing. In fact, 8-10 hours of standing puts a lot of pressure on the back as well as the muscles in the legs, increasing chances of varicose veins later on.
You need physiotherapy besides the Ibuprofen that you are taking, because Ibuprofen by itself can't reduce the pain till the root cause is eliminated. So, kindly schedule an appointment with a physiotherapist and go for 8-10 sessions. This will definitely help you.
Feel free to discuss further,