My Left Leg From Thigh Down To Calf Area Is

my left leg from thigh down to calf area is sore and throbs in the evenings, I fell at work a week ago twice. Once while I was vacuuming my left knee just took the noodle effect and down I went, I was a bit dizzy afterward, and my visiy since I fellon was a bit blurred for a little bit. When I felt better I got up agin made several steps and fell again. I noticed any kind of wait makes it just want to act like a noodle and I have to relay on other leg quickly before I fall. Also have noticed the weak knee more so lately, since falling.