Thinking about dropping due to injury. What would you do?

Hey all. Hoping for some advice from more seasoned runners. I’ve been training for the Rocky Raccoon 100k coming up in about 4 weeks. Will be my first 100k race. I’ve completed a few flat 50k races over the years and many marathons. Fastest 50k I’ve done to date was right under 5 hours, during this training block in late November. Unfortunately, at about mile 30 of that run I started to develop some significant pain at the lateral part of my knee pretty consistent with ITBS. It didn’t bother my at all until that particular part in the run. I was able to finish the 50k and the next week was a built in recovery week which helped with the pain (total mileage that week was like 25 miles). Since then the knee has continued to be an absolute mess for any run longer than 3 or so hours. We’re talking pain that basically stops me in my tracks at a certain point. All my shorter runs, basically anything less than 3 or so hours, is totally fine. Zero pain.

Today I had a planned 50 mile run, the longest of the training program. Felt great for 20 miles and then stopped to refill my flasks for about 10 minutes and the pain started immediately when I got going again. The next 8 or so miles were pretty bad, and I eventually gave up at mile 28 and called the wife for a ride. In a tough spot mentally.

I’m a sports doc here in the states so I have some good resources. I’ve been working on my glutes and core since I started feeling pain in late Nov, I’ve done foam rolling 4-5x weekly and recently one of my colleagues did a cortisone injection under the ITB for pain (very helpful for about a week). I will admit that strength training was lacking in my current plan and is likely where my issues have stemmed from.

I think I’m at a crossroads. A part of me wants to just shut down running completely over the next 4 weeks, get into PT and slowly work myself back up. The other part of me is wondering if I don’t back off significantly over the next few weeks and make it a very long taper to try to get to the race. At my base, I typically put in about 30 miles weekly (when not training for a race). Over the last 8 weeks I’ve averaged between 45-50 miles a week which feels like enough but the problem is that my longest run was back in late November and was only 50k.

Tough spot for me and I’m super frustrated with myself. If you were in my shoes what would you do?