Why does the side of my leg hurt and why do i got blisters only on the left side of my feet?

Hello I have always had blisters on my left foot on my heel and not on the right foot. when I try to walk it hurts and annoys me. Also when I walk, I get this pain on the side of my legs between the knee and the ankle like on the side towards my outer body area not in the middle. and the area gets swollen.I dont know why? I have some thoughts what it might be Im very obese and also the sides of both feet on the pinkie toe area side strech out the shoes i wear like if im making my feel lean towards the right and left but im just standing normally. I think I have high arch feet as well because I have had heel pain. Do i need special shoes or something? what do I do to stop the pain, and make the blisters go away is my left foot smaller than the right thats why I get blisters only on that one? Ty in advance for the help

[Yena H Do, DPM]

i would see a podiatrist to get a biomechanical exam.
you could be placing more weight on the sides of the feet, thus causing increase friction and blistering.  a special orthotic could help redistribute the weight on the foot and offload the outter foot.
if you have high arches, an orthotic will help provide support.