HELP! Fahaka puffer owners! Jerry’s fins are white

Any help / advice is greatly appreciated. I’ve recently gone through a bad depressive episode & haven’t been able to keep up with water changes. (I’m a bad mom, I know). I did a 50% water change today & cleaned the filter / added new filter medium. The tips of my Fahakas fins are white / opaque.

What can I do to help him? I’m afraid it’s a bacterial infection that happened due to my neglect. If something happens to Jerry I will be so sad.

He’s still eating & swimming around so I’m praying it isn’t too late to treat it.