Don't give up!,I find that most of the time the patterns are way off from real world sizes. You've gotten this far,go ahead and make the adjustment, what's the worse thing that will happen...an addition to your scrap pile! one of the issues may be that you used 1/4 seam allowance versed the 5/8 for sewing garments. I would just leave the seams that are in it now and just keeping going in a 1/2 inch at a time. I wish I could come help! Good luck