Going by the way the fish ignored the food in your video and that he has not been interested in food since last weekend along with the bloating.......I think it might be too late to save him tbh
It's hard for us as outsiders to judge on whether to euthanise when its your fish and you are standing there watching him. But at the end of the day if you feel that his quality of life is not good and is getting worse, then euthanising is the right thing to do. None of us like euthanising fish but if they are ailing, not eating and have body issues like this, then we have to put our feelings aside and think only of the fish.
My personal opinion, going by the video, photos and what you have said....I would be inclined to euthanise. I'm sorry