Pineconing treated with Maracyn twice - do I continue?

[Anomaly16]

10 gallon planted with 2 sponge filters.

Water parameters:

Temp - 78F

Nitrate - 0 (I know, I need to feed my plants, I've been worried more about the fish lately)

Nitrite - 0

GH (ppm) - 300 (I think - aquarium coop test kit, light lavender)

KH (ppm) - 80

pH - 7.2

Chlorine - 0

Ammonia - 0

Okay guys, I don't know what I'm doing. I'm still fairly new to the hobby, but I've been trying my best to care for my betta, Mushi. I got him 8/31/21, so I haven't had him long, but he's already been scaring me to death this month.  I feed him Hikari freeze dried daphnia, Hikari betta bio-gold, and frozen spirulina brine shrimp. I only ever accidentally overfed him once at the beginning of this month (with the brine shrimp), and I think that's where all this started. I fasted him for 2-3 days after overfeeding (he had gotten bloated), and his bloat did decrease significantly to where he was either back to normal or close enough to it that my untrained eyes couldn't tell. I fasted one more day just to be sure.

The next day I couldn't find him anywhere and was really starting to worry when I found him hiding/cornering between two floating plants.  He had no appetite despite the several day fast and had actually bloated up again.  Water parameters were similar to what I outlined above; only difference was probably nitrates but still within acceptable range. I did a 10% WC anyway and added a catappa leaf. 

The day after he was still hiding and had severe pineconing.  I did a 5% WC just because, but was pretty much panicking so I started medicating with Fritz Maracyn. I did a full course treatment (5 days, no WC). He got his appetite back on day 2, energy back day 3, and bloat was down day 4 but the pineconing was still pretty severe on his left side (whitish at the base and looked like some scales were going to fall off).

On day 5 his pineconing was significantly reduced, but there was a circular white area with what looked like a singular stringy white strand right behind his left pectoral fin where the pineconing (and bloat) had been the worst. I think he did lose some scales and this was the result. The stringy bit was gone the day after and the sore or whatever it was rapidly healed. I also did a 25% WC.  Also, that's not ich or a sore on his face, he swam past some detritus caught in a floater's roots.

Again, to be safe, I rested him a couple days like the package says and then did another round of treatment (1 packet/5 days).  The last day for that was 11/14, and I still saw slight pineconing. Nowhere near as bad as before, but I think any is bad.  I also did a 25% WC on the 15th and did a 10% WC today (will probably do 10% every other day unless someone gives me different advice).  

The rest of the photos are from today (11/17/21).

He also still looks slightly bloated, though not as bad as before, and I've been feeding him every other day.  I'd say I'm even feeding him incredibly sparingly, just one meal a day, no bigger than his eyeball.

So all that to ask, do I treat him with Maracyn again? Do I just keep treating him until he stops pineconing? He's already been through 2 full courses of treatment so I don't know if that's the right move. Should I try an Epsom salt soak for 15 minutes like I've heard? I'd have to pick it up tomorrow.

And not only all that, but I'm wondering if I should be concerned about the state of his poop? I know it can be an indicator of health issues and, well, he's pooping in the pic so I guess you can tell me if I need to change up his diet.

I don't know what to do guys and I'm feeling really discouraged. I'd appreciate any help.

[Colu]

If he still pineconing I would treat with kanaplex as it adsorbed thought the skin and gills of fish and it good antibiotic for treating kidney disease which is is common cause of dropsy and aquarium salt 1 table spoon for 2 gallons it will help reduce the fluid buildup which is the cause of the pinecone apprance

[Anomaly16]

Would you treat with kanaplex and aquarium salt at the same time or alternate somehow?

[Colu]

At the same time as the salt reduce the fluid buildup while the kanaplex attacks the bacterial infection or kidney disease

[Anomaly16]

I will try that. I'll have to pick some up tomorrow. Thank you!