Thanks for posting your query
You felt on your left hip & after that you developed pain & swelling over your left hip.
you might be suffering from soft tissue injury
to your left hip.
If you had decrease range of motion at hip and tenderness present , then it might be a fracture
So you need an x-ray of hip.
So you have to visit an orthopaedic surgeon
for exam. of hip &back and x-rays as required.