I am feeling a sharp pinching feeling inside my left inner thigh also sharp pain left lower back all the way down my leg, what can it be?

Possible disc: Pain in back with radiation into the leg is suggestive of nerve root compromise in the lower back. In your age group this most commonly is due to a disc herniation. Would suggest orthopedic or physical medicine evaluation.

Disc Herniation: You almost certainly have a disc herniation in your low back leading to sciatica. Most of these (90%) will resolve with rest, light physical therapy and time (6-8weeks). However if you develop weakness or sensory loss you should see a neurosurgeon asap as this can require surgical treatment. An orthopedic surgeon is also an option but you'll need to ensure they have additional spine training.

Pinched Nerve: Sounds like you have a pinched nerve in your back. I would suggest seeing a pain/spine specialist to evaluate you further to evaluate what level and what can be done to treat you. There are interventional treatments besides medications and surgeries that might reduce or eliminate the pain altogether.