Trellimars Battle With Dropsy (Advice Appreciated!)

[Ammolite]

Thanks to help in a previous topic I found that my betta, Trellimar, is suffering from the early signs of dropsy. I moved him straight into a hospital tank (3Gallon) to try and improve his condition and hopefully, save him. I thought id post a topic on his situation for advice, and as a daily update to see if anyone could help me tell if his symptoms are worse or improving. 
He is my first betta and id do anything to try and save him, but i know the inevitable may come, i just hope I'm helping him live out his days peaceful and in as little pain as possible. 
 
 
Medication used:
- Nutrafin Betta Plus 
- Melafix
- Stress Coat
- Water Conditioner
 
Water Conditions as of today

Ammonia: 0
No3: 50
No2: 1
GH: 8
KH: 15
PH: 8.4
CL: 0
 
 
Day 1:

Moved straight into a hospital tank, no substrate at the bottom and one fake plant large enough to hid in as well as rest on in the tank. Heater is set to 80 and no filter as per yet (it has a strong flow) I plan to change the water by 50% Daily.
He's resting at the bottom of the tank a lot, refusing to eat and swim around. He has bloodied bottom fins after being attacked by a tetra (who has now been returned to the store) before he was moved and has lost all the white to his half-moon butterfly tail. He is bloated and is pine conning. 
 
I plan on not feeding him for 3 days then giving him the pea treatment, is this recommended? 
 
Day 2:

He is up and moving a lot more now in comparison to day 1, not as active as a normal betta though. Has made a small bubble nest above the plant where he rests most of the time. Haven't seen him on the bottom at all but he lounges at the top. His fins are no longer bloodied and the red has cleared up well.
He is still very bloated, lethargic and is still pine conning. His tail and bloated tummy are slowly turning white. 
 
Water Conditions as of today
Ammonia: 0
No3: 25
No2: 1
GH: 8
KH: 15
PH: 8
CL: 0
 
Pictures of him from today 

 

[Ammolite]

Day 2

He later died this evening after putting up such a good fight <3 My precious boy, I sat with him till it was over. Swim in peace <3 
 
Does this occur in Dropsy? I know it can do weird things to fish, but Trellimars tail rapidly turned grey and disintegrated at the ends. I don't know if this was because it was Trell's time or what. Photos as follows~
Ammonite is still perfectly well, and the aggressive fish has been removed from the 7 gallon. 
 
 

 

[LyraGuppi]

I'm sorry about your loss. Dropsy is so hard to treat once it's set in. The fins could be a result of the immune system failing, it looks a bit like fin melt.

 

[omega59]

I am sorry to hear he passed away, will you be getting a new Betta?

 

[Ammolite]

Thank you, both of you <3 
 
Thank you Lyra, after looking at it yeah it does seem a little like that, and immune systems failing seems like a logical reasoning as to why it happened so quickly :c
I currently have another betta fish Omega His names Ammonite and is an unknown breed and colouration to my knowledge~