While the information you have sounds negative. There’s really no way of knowing anything until you get a biopsy.

PIRADS 4 Doesn’t definitely mean you have prostate cancer or that it’s aggressive. The ExoDx Score is high, But you don’t know what your biopsy shows yet so it’s really not possible to guess what’s going on. A high score does not automatically guarantee that cancer is present, but it strongly suggests that further investigation is warranted

A 77 could mean you have a chance of a Gleason seven or higher, not that you have something that’s not treatable. You could live for decades. You just need more information.

Definitely not time to panic since prostate cancer is a chronic disease for almost all of us these days.