Sick betta with multiple problems

[hedgehog]

I wanted to get advice on treatment. I went to do my weekly waterchanges today and noticed that Frost has pop eye and the start of columnaris. I caught both of them very early. I know he was fine yesterday. I went out to get treatments but Petco was closed. I got Jungle Fungus Clear from Walmart in addition to plain epsom salt and aquarium salt. My question is what should I treat first. I was thinking the columnaris. I don't know what treatment for columnaris to start with. I also have to treat him in his 5 gallon tank. I've never dealt with anything other than finrot. Advice would be much appreciated!

I filled out the questionaire but I'm pretty positive about what he has.

Housing
What size is your tank? 5.5
What temperature is your tank? 78
Does your tank have a filter? yes
Does your tank have an air stone or other type of aeration? no
Is your tank heated? yes
What tank mates does your betta fish live with? none

Food
What type of food do you feed your betta fish? Topfin betta pellets
How often do you feed your betta fish?Everyday 3-4 pellets in one meal

Maintenance
How often do you perform a water change? once a week
What percentage of the water do you change when you perform a water change?25-50 usually closer to 50
What type of additives do you add to the water when you perform a water change?API tap water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia: Don't have a kit
Nitrite: no kit
Nitrate: no kit
pH: 7
Hardness: no kit
Alkalinity: no kit

Symptoms and Treatment
How has your betta fish's appearance changed? cloudy eye, bigger eye, little bit of fuzz between eye and mouth
How has your betta fish's behavior changed? just laying in plants, won't eat
When did you start noticing the symptoms? all symptoms began today. He was normal yesterday
Have you started treating your fish? If so, how? Nope got some supplies but wanted advice first
Does your fish have any history of being ill? never been sick
How old is your fish (approximately)? 2.5 years old

[IndeedPanda]

Maybe clean out your tank 100% and clean the substrate andrinse any plants and ornaments- just really clean the tank and everything in it. It might be a cycled tank, but if your fish is sick you gotta do what you gotta do.

Try maybe getting him a small QT fish tank and putting him in it. Change the water in the QT on a daily bases and sanitize your other tank and start the cycling over again. Treat him with Melafix and I think people have been talking about Rooibos tea and epsom salts. Try a teaspoon per gallon or freshwater salt from a fish store. Don't worry too much about him not eatting. They can go a week without food if they must, but see if you can't get him to eat.