This is a difficult fight.
So I was also really frustrated with this for a long time and finally decided to look at a video of someone completing it on normal (with on-screen directives) to see if there was some sequence or combination I kept missing.
Where I would keep running into trouble was the grapple sequence where Talbot has you held from behind and you’re eventually supposed to bite him. I could never seem to trigger that as Talbot would always end up just pushing or rolling me away, but that seems to be the key to progressing through the fight. What I gleaned from watching the video on normal mode is that there’s actually a subtle pattern/rhythm to this sequence.
Rather than just aimlessly mashing the circle button to no avail (what I kept trying to do for what seemed like forever), there’s a point in the middle of this sequence where you’re supposed to hold circle down for longer (or harder?) once and then resume spamming the button. It might take a few tries to get this pattern right but after I watched that video and tried it out, I finally got lucky and triggered the bite once and pretty soon thereafter the fight was over. It’s hard to get it right and might take a few attempts but if you play around with it a few times and make a concerted effort to transition from mashing circle around 4-6 times, then pressing down on it more emphatically/longer once, and then immediately going back to mashing it a bunch of times, Nathan should finally bite Talbot.
Not long after that, the sequence where Talbot switches the knife to his other hand also finally triggered for me (luckily as others mentioned you don’t seem to have to avoid getting cut here to progress, just make sure he doesn’t slash you a second time on "crushing" difficulty unless you want to start it over again for the 573rd time but who’s counting at this point haha).
Then, after a few more counters (triangle), offensive strikes (square), or the other pattern where you just button mash circle as fast as you can to ward off the knife, you’ll get to the point where Talbot has you pinned near the edge and for the rest of the fight the game will now automatically give you on-screen directives regardless of difficulty.
it’s spamming the circle button as fast as you can, which you should be a pro at by now.
I am not sure which if any of the other sequences are necessary to successfully complete the fight, but I don’t think you can progress until you bite him once and that was by far the hardest task for me since simply hitting circle as fast as I could would only end with Talbot rolling Nathan away instead of Nathan biting him.