Totaling responses from a field?

This is a pretty beginner question I think but my brain is fried today.

I have a spreadsheet with 3 columns. The first two I don't need at all. The last one is the filled with answers to "How did you find us" on our checkout page. I want to make a graph or pie chart that totals all the answers and shows the most common responses by percentages or count.

The column's data has several pre-filled answers they can select, but they can also write their own so there's tons of custom responses. I don't have a way to reformat it so each response is in it's own column which I think is what I need to do to properly display it?

Any help would be great!