Sorry to hear about your waistband issues. At the end of increasing the waistline tutorial, I do go over increasing the waistband. You do increase the waistband by the same total measurement that you increase the waistline. I don’t have this pattern so it’s hard for me to say things for sure but it’s easier to understand if you breakdown the waistband. Remember there’s going to be seam allowances and maybe an overlap for button,snap, hook and eye, etc. Once you remove those aspects you have the size of the waistband. Compare it to the measurement you need to get, you’ll not be dividing it by four because there are not four sides to a waistband pattern, instead I divide by 2. You’ll notice that I increase at the side seam area of the waistbands. This is so I don’t throw off my notches. If you give up and just increase at the end of the waistband, your waistband may fit perfectly, but just realize your notches will just be off. As long as you make allowances for the seam allowances and that overlap for a button then no one will know but you. The waistband, in a lot of cases, is just a rectangle so it’s not the end of the world if the notches don’t match as long as you have that overlap if you’re supposed to. Hope this helps.