Make sure for a betta so severely stressed that the water level is low and the water nice and warm..like 84 (which is invalid betta comfy). Leave out the melafix/bettafix for now since you have that broad spectrum.
Actually depending on your heater size and severity of her attitude, she may be better served by being in a shallow container of bowl like shape that can float an be heated yet only deep enough for her to have to stretch for air. And change 100% that water frequently..every other day in the bowl, every third day (or with teh re-medication if on a 4 day) in 5 gal
or less. Keep those wounds cleaner than clean for at least a week and she will prolly start coming up.
I wish I had more to offer but I have only brought one seriously injured fish to health with success. And I ALMOST saved a dropsy fish..
But almost only counts for horseshoes and hand grenades
It was unfortuneate that she was nosy and small enough. My betta couldn't get more than his mouth or tail stuck in the tube..so he is relatively safe from his foolish attacks in the vacuum.