Task bar became wider in length.

I have Linux 17.2, Cinnamon 2.6.13. I turned my computer on one day and the task/panel bar had extended in length. This caused the 1st icon on the left to no longer be displayed. Also, only half of next icon is showing. I need to know to restore the correct length back/how to shorten the width of this task bar. I need the first icon back because it is my start menu icon. I don't know how to bring up the start menu any other way. I have tried everything that I new how to do as a newbie, but my knowledge of linux is almost nothing. Please help me!