The fish definately got Hex and you've left it way too late to treat. It also appears to have fin rot .
To be frank, not worth saving (that's my opinion). I would put the fish out of it's misery.
But if you want to treat thendo as follow
Raise temp to 33 deg and make sure you have plenty of airations.
Dose with Trichozole (Metro) 400mg per 40 ltrs water.
Repeat daily after 50% WC for 10 days.(Same temp water as tank for WC)
HTH,
ron