I’m devastated (tw last slide)

My favorite betta passed away after only two months of ownership. I did a 20% water change and i thought he was just a little upset but after i saw 3rd slide i gave him some kanaplex. Next morning he passed away. I don’t know what i did. He lived in a heavily planted tank. He was happy. no ammonia. I made a joke at the lfs that he passed and i regret it. He always came up to me whenever there was food. He has wild type so he was super kind. I miss him.

PH: 6.8 Nitrite: 0 Nitrate: 0 Ammonia: 0