Push on or suck it up? (Pride or common sense)

I'm posting this while sipping a cup of hot tea and watching the occasional  snow squall from Ma Nature. On April 19!! What the ?!@$ The crappy and unseasonable weather isn't helping my mood or my training. I've got my ultra in less than a month, and I've been on the trail once. In the snow!!!
Which brings me to the thinking for this post. I'm not sure if it's all the road miles, or just all the miles, but my body is starting to rebel a bit. I guess I'm not the genetic freak some of my kids think I am. Nothing serious (I think) but my feet are starting to complain. Yes, I've seen a medical professional, so I'm not self-diagnosing!! It's mostly arch pain, sometimes in both feet. Now it's spread to the top of one foot. My original thought was plantar fasciitis. That doesn't seem to be it. It stays around constantly. Doesn't go away (usually) throughout the day. The ache on top of the foot can really get my attention if it tries!
So what does this have to do with pride or common sense? I'm signed up for the Ice Age Trail 50 on May 11. 50 miles. I'm beginning to think the feet aren't going to put up with the distance. I've notched a 50K on the road, plus a few more above 20 miles. Add in a handful in the teens. After my latest 27+ miles, my feet weren't happy with me at all. The rest of my body was fine with the miles. My feet and I are no longer on speaking terms. I've been icing, heating, rolling and talking nice to them. Apparently they are stubborn piggies! So, do I suck it up and press on regardless? I know, long miles hurt. It ain't a walk in the park.  Maybe take a chance and screw up the rest of the season. Or do I try and contact the RD and see if I can move to the 50K? I know I can do that. The prospect of starting the 50 miler and DNFing is a thought I don't like. I've been running, biking and xc skiing for 30+ years, and have 3 DNFs-all mechanicals. I like to think I'm tough and won't give up. But, I've realized I'm not in my 20's, or even my 40's, anymore. I want to push myself, but I need to be smart too. My job doesn't allow my to relax and put my feet up either. I need to get up and head to work six days a week. Time off due to injury isn't an option. It would add insult to injury if it was a case of hard headedness and self induced.
I need a few days to think and mull things over. I know the taper that is coming up will help. And I'm not even sure moving down is an option. If not, I give it my best and take the miles as they come! I'll let ya know what happens.
Thanks for visiting!
Sven