Hi , Welcome To HCM & Thanks For Asking Your Query Here As you are going through a viral illness there are possibility of Infectious myositis as It is especially common among people who have the flu (influenza) and it is muscle inflammation which damages the fibers of a muscle leads to muscle weakness and severe pain ,Although myositis can cause muscle aches and muscle tenderness, weakness is usually the dominant symptom mostly it is a short-term problem that goes away after a few days or weeks. but it needs medical attention to get it treated However your Throbbing thigh pain can emerge from the knee, hip or back. The origin of the problem could be related to the muscles, bones or nerves in the legs You can take Over the counter Medicines like Ibuprofen and thiocholchicoside to relieve pain , also do some walk and apply heat packs , warm bath can also help but If it continues after a few days of home treatment, you should see your doctor to rule out the underlying issue I hope it help Thanks & Get well Soon