If/then/add statement; Multiple if's, then get fields, and total in that field

If you have a numbering system for naming your fields it would make things a lot easier for you.  Without consistency in field naming you're going to end up with monster script subject to errors for a simple calculation.  You had a lot of errors in your scripts, mostly lower case f's in this.getField, which you can find by checking the console for errors.  I renamed the first row of your fields, deleted the rest, only entered one script into the first TonsYes field, then used the technique in the article linked above (Right-click > create multiple copies).  Then I wrote the script in the 3D field.  I also used "Sum of" in field 3C.  You only have to select one field (Tons in this example) when you name the fields properly.  See attachment.