Video What's happening to my fish?

I don't know what happening to my gourami, these days she's not energetic and there's a small black swelling on her belly. Is that any kind of sickness? Please help me

Hi and welcome to the forum

Are they both pink kissing gouramis?

First and second picture have a pink gourami with a black spot on the bottom half of the body. this looks like a bacterial infection.

The third picture has 2 fish. One of the fish has black patches over its body and pink on the top of its face. The black patching is normally chemical burns caused by chlorine/ chloramine, or overdosed medication or plant fertiliser.
The pink area on the face is a sinus infection caused by bacteria, virus or protozoa.

Make sure the water quality is good and there is no ammonia or nitrite and the nitrate is less than 20ppm.

Do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it unless the flow is reduced.

See what the pet shop has for bacterial infections

Thanks for replying me
Yes,both are pink kissing gourami.
That black patches in the 3rd picture were in there when i bought that gourami and there's no problem with that, he's healthy

But the other one in 1st and 2nd picture is getting weak day by day.

the gourami with the bacterial infection is going to die unless it is treated asap. Even then it might be too late depending on how much damage has been done to its organs.

the gourami with the black patching has the inflammation in its head. that should clear up after some big water changes and gravel cleaning.

I have actually seen that from over feeding. If your fish become constipated and food builds up in it's stomach. It can rot before being digested. Not saying that is what it is. I would treat as recommend above. But unfortunately might no be much that can be done.

P.S. hope he/she makes it. Sucks having sick fish. Just had a female Betta beat wasting disease. Always a feeling of dread looking into the tank hopeful your fish is still alive.