Betta Fish: Update + advice needed

Hello everyone

I posted about my boy a little while ago, when he had gotten a cut on his tailfin (https://www.reddit.com/r/bettafish/s/egm1o03j5z). Since then, he seems to have gotten much worse.

Since the first tear, I had removed everything pointy and kept the water clean, with more frequent water changes (2-3 times a week). I have only seen his fin worsen in this time.

Water parameters:

Ammonia: 0,0

Nitrites: 0,0

PH: 7,2

Temp: 27°C

Would you say this looks like fin rot, or just slow-healing tears? Should I start on antibiotics (no access to almond leaves currently)? I have access to a hospital tank, if needed.

I thank everyone for the help in advance!