Arduino sketch taking forever to upload, followed by multiple issues
When the Arduino IDE says its uploading but never uploads, it is most likely a COM port issue. Try plugging the Arduino in a different port and make sure you change the port in the IDE. The problem seems to be you have changed the Arduino port, but not in the IDE. The Arduino IDE registers the previous port as open and tries to upload the program to that port. Go to Tools &gt; Serial Port and it should list the ports(example):

COM 2
COM 3
Arduino Uno at COM 4
•COM 4


Every time you unplug and replug the Arduino you should check your ports and select the appropriate one ( It usually says Arduino *type* at COM *port number* 

COM 2
COM 3
•Arduino Uno at COM 4
COM 5