iCal will not sync with Exchange work calendar

Hi

All of a sudden my iCal will not sync with/ show my exchange calendar. The emails are showing up but the calendar isn’t. The iCal is where I manage all my competing priorities personal and work together. I have tried resetting my iPhone/ deleting my email account and reading it/ going from data to wifi / changing the default calendar to my exchange calendar/ updating passwords in my password settings area/ to no avail.

I have downloaded the outlook app and can see my calendar there but it is of course separate from my iCloud personal calendar and I really need to have them on the same app/ location so I don’t overbook or cross book myself.

HELP!