Sore blister on bottom of left foot only and always on left one will burst then another will come up a week or two later they can look clear or milky?

Clear: Sounds like a form of athletes foot, but milky does not. Why not see a doctor and get a diagnosis and treatment....

Possible Protection.: There are only a handful of reasons one could be having blisters on the bottom of one foot. First of all, blisters a small, less than half an inch, while blebs are bigger. They can be clear or slightly milky. They are primarily caused by friction, but a reaction to touching something can be the culprit. Since it involves on foot, consider a repetitive increased force to that one foot or a fungus.