75 Gallon Tank What's wrong with my Golden Gourami (Three Spot Gourami)

[Angelfish1]

My golden gourami always swims wierd, almost like he's struggling. This has been going on for quite some time now (I think since August). I initially thought it was gourami aggression so I put him in my other tank with Angelfish. Recently I noticed he's been getting worse, I assumed this was because he was a slow eater and wasn't getting enough food. I honestly don't know what is wrong with him, if it was only the food he'd be chasing things and trying to eat, but he seems to be struggling to swim properly and just be a gourami(?). My other two gouramis (One three spot gourami and one blue gourami) are very active, can swim very well, eat well, and are doing very well so this isn't a whole tank problem. I'm attaching a google drive video of him today here. It's not in the video but he'll also shoot up really fast from the bottom of the tank and almost jump out of the water, I think it's because he needs to get to the surface but he doesn't have a lot of energy to do it normally. I separated him in a small container to feed him but he didn't seem interesting in the food, so I don't know what's going on.

 

[tomiyama]

Does he ALWAYS do that? Something is wrong then.... perhaps swim bladder disease....

 

[Angelfish1]

Does he ALWAYS do that? Something is wrong then.... perhaps swim bladder disease....

Yup, if not this he'll just stay still at the bottom of the tank.
Swim bladder disease seems likely now that I'm looking into it. I heard the fish isn't bothered by the disease but I'll make sure to separately feed him from now on to make sure he's getting a sufficient amount of food. I was just worried it's something deadly.

 

[tomiyama]

Be careful not to overfeed.... some people say to feed a small amount of peeled (skin off) cooked pesticide-free peas for constipation but not sure if that will help at all, I would feed very cautiously.