What could be causing pain in my lower back that gets worse throughout the day? also, pain in my right hip, knee and ankle especially at night.

Orthotics may help: It sounds like you could also have a biomechanical instability in your feet that is passing problems 'up the kinetic chain.' custom made prescription orthotics, made by a certified lab, under the recommendations of a podiatrist can help tremendously!

Sounds like its : Your back is the cause. I would see neurologist or orthopedic spine surgeon.

Nerve compression: Possibly nerve compression from different structures on the lumbo sacral area. Consult a neurologist for further evaluation and treatment.