Runners Knee/ITB-S pre Philly Marathon

Hola amigos.

Unfortunately I, like a few others, underestimated how tight my IT Bands were getting until IT Band Syndrome flared up two weeks ago during my 18 mile run. The pain hit around mile 6 but was manageable if I ran faster than normal (weird but that’s what I did) and finished. But definitely pushed it too much. Making walking the next 2 days afterwards painful and felt like my knee was ‘unstable’ almost.
The next day I began all the PT and stretches I could find online to help, but otherwise took a full week off running and biking. Then in an attempt to will it to go away I suppose, I ran more than I should have this Sunday and was the same thing over again.
Realizing this won’t just go away immediately I’m continuing glute, tfl, outer quad and hip flexibility with targeted foam rolling daily.

Other than rest and working on the surrounding muscles that caused the tightness in the first place, via the practices I mentioned above is there anything else I can do?

If that’s about it, how long should I expect to be doing zero running (with proper PT work)? Is a Philly Marathon feasible in 24 days?

Lastly, I just went on a rather short and very leisurely bike ride and felt zero discomfort, so could biking be okay as long as it doesn’t cause discomfort?

Thanks in advance yall 💙