I have burning, sharp pain on my left thigh, seems like its growing down my leg, my foot is getting some pain too in my big toe and on the left bottom m?

Nerve pain. Sounds like radicular pain, nerve pain. May be sciatica. Most LBP is not serious and goes away with time, physio, and simple analgesia. Warning signs include numbness, weakness, urinary or defecating problems, or fever. If you are older or have a cancer that is concerning also. If any concerns or symptoms persist you should see your doctor.