Betta Fish: i’m kind of at a loss

so my fish was fine for a good few months, but i had some water problems w ammonia, bacteria, and algae. my tank has finally settled but im noticing his fins are wearing more and more. i can’t tell whether or not to treat with medication bc they don’t look rotted, but each week he gets worse and worse and im not sure what else to do

1st pic is two months ago, 2nd is last week, 3rd is this week.

i know he’s likes to dig so i added sand patches for him so that he wouldn’t be ripping his fins, but now idk how his back fin is getting small rips, his top fin i thought was hitting the side of my airline tubing so i took it out, but now there’s holes in it. i can’t tell if it’s fin rot because he’s acting normal and there’s not really any discoloration. pls help!