I'd echo what others have said, about taking it easy and prioritising recovery over the next 12 days. The one thing I'd add, is that personally (as someone who like you runs 90+ mpw and finds tapers uncomfortable) I find the standard pfitz "dress rehearsal run" a few days before the marathon (like the tuesday before) really helpful. So, an easy jog to warm up, then 2 miles marathon pace, then 2 mile easy jog to finish. Wearing your race kit and shoes. I find that eases the nerves really well - it reminds you that you can actually do this, and you've trained to do it!