Why is my goldfish going crazy?

After we moved the aquarium to the aquarium stand (it was on the table for 1 week until we got the stand), now it is swimming crazy on the side of the aquarium, but it’s just on ONE side, THAT side of the aquarium that faces the wall. It goes left and right, up and down… kind of swimming in circles and quickly, very quickly that I can’t see if there’s a parasite or not, I mean, as far as I could see, there’s nothing on its body. It’s funny because on the table one side of the tank was facing the wall too and it wasn’t crazy like that. It was always very “happy”, if I can call it that, swimming around, checking the gravels, reacting when i got closer, but it’s going crazy now, it’s funny, but i don’t know if it’s normal. I just changed 25%of water, vacuumed gravel, added salt, conditioner, have a bio filter (the one that the water falls into the tank) and added 1 air stone yesterday. There’s not too many bubbles, I’m controlling the air, but we did add the stone just when we moved the tank.
Sometimes, but I’m not sure because it moves too fast, when I can see it coming on my direction, it seems a little inclined to a side. But I can’t say if that’s really happening because if I look at it from another angle of the tank, it doesn’t seem inclined.
Also, I’ve seen it going to the surface, like getting air from out, is that normal? I hadn’t noticed before.

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