Thanks for posting your query
You had injury over right side of your buttock . After that you developed swelling & it is tender to touch.
Also you are unable to bear weight on that limb.
It might be a soft tissue injury
or a fracture
You need an x-ray to rule out any fracture.
So you have to visit an orthopaedic surgeon
for exam. of lower back & hip , & treatment plan acc. to that.