Thanks for posting your query.
From description, it seems to be soft tissue injury
over your arm. Generally it takes 10-15 days to heal.
I suggest you to consult an orthopaedician nearby for a detailed examination. You may get the X-ray of the area affected under his/her guidance to rule out any bony injury.
In the interim, you can take anti-inflammatory drug like motrin
to reduce pain and inflammation.
Avoid lifting and rest well.
Wishing you good health
Dr Saurabh Gupta