You have symptoms of swelling of area between collar bone and shoulder as well you have pain at the same area and the arm. Here one thing is good that your pain is reduced from the time of fall in 5 days but there is swelling which is increasing is not a good sign it shows there is inflammation increasing. Here I will suggest to visit ortho doctor and take x ray to see there is nothing major damage in your soft tissue and bone. Now here ortho will also check with some physical test and then based on report and diagnosis for minor to moderate issue he will suggest for physio treatment and conservative management. You can also use cold pack to swollen area to reduce inflammation. For any thing major damage ortho doctor will suggest for either pop plaster or surgical correction in case if there is damage to bone( fracture) or soft tissue injury ( major cut ). Till the time you consult doctor I suggest to take some conservative steps like immobilise your shoulder close to body that means do not move up and down or stretch out side for time being and keep using cold pack frequently to reduce swelling. Along with this you will have some pain relief but do consult a doctor for proper diagnosis and treatment. Here I have given you general guideline on treatment I suggest follow it step by step and I am sure this will be helpful for you. Take care.