Peroneal Tendonitis ahead of NYC marathon

Hi!

I believe I developed peroneal tendonitis about a month ago. I’d taken 6 weeks off from running due to just an irritated hip flexor, and then when I got back to running, I was so excited to be able to do it again that I did way too much, way too fast. After about a 40-mile week and then a 16-mile run the following week, i quickly developed a pain around my outside ankle bone (mostly under it) that sometimes goes up to my knee on the outside of my leg.

I have super high arches, I’d been running downhill more than usual (just moved to brooklyn and the first 2 miles of my runs are always slightly downhill), and I run fairly fast. So according to my internet research and where i feel pain, it seems pretty likely that it’s peroneal tendonitis.

I got into the marathon last minute about two weeks ago. I took 3 full weeks completely off from running, but now I kind of need to start training. If i just start training through a little pain (it’s actually not bad at all while I run - it’s really only bad for the first hour in the morning), can I just make it through the marathon and then realllly take time off to heal it? i don’t mind dealing with a little pain. i just dont want to do permanent damage. and also any advice on how to mitigate the pain a little or heal it (while still running) helps!!! (i did 8 miles yesterday no problem, with no pain during the run, only pain this morning when i got out of bed. to give you an idea where it’s at)

THANK YOU in advance for any and all advice!