Betta Fish: cyst or tumour ?

i cant tell if this is a cyst or tumour, as well as if hes got fin rot or fin nipping. i feel like a terrible fish mom and i genuinely dont know what to do here. ive given him 2 15min salt baths in the last 3 days and the darkness seemed to lessen a little bit. hes in a 5gal with no tankmates, live plants, heater, filter, hides, and temp stays at 79-80°