Drop down menu too long and clipping

Hi guys,

So I have been trying to deal with this problem for the last 10 hours, and I am at my wits end!! I have a menu that has lots of children, grandchildren and even great grandchildren. One of my menus is too long for the page and is cutting off. If I make the container bigger generally, width: 500px. I get 2 columns and it looks good, however it makes all the other dropdowns 500px and by the time I get down to the third tier, the menu is off the page and not visible.

I know this is not a new problem I have read of lots of cases, but all the code I have tried has failed. I am using Elegant Themes Divi theme (their support has been no help). I have a box in the options selector to add custom CSS code.

All I want is for the box to be 500px wide when it needs to be, then the other shorter menus to be 250-300px wide.

My site I am working on is fun2do.site

Please help I have no fingernails left, my hair is thinning by the second!