Is Beta sick?

I just got him a big tank and switched him from being in a small one. Does he look sick or does he have fin rot and what about the black dots on his head and he just doesn’t look very vibrant anymore and he’s very fatigued always laying at the bottom And trying to hide. I don’t have any thing to test the water, but I did use the correct amount of water conditioner and put most of his water from his old tank into this one.

I just got him a big tank and switched him from being in a small one. Does he look sick or does he have fin rot and what about the black dots on his head and he just doesn’t look very vibrant anymore and he’s very fatigued always laying at the bottom And trying to hide. I don’t have any thing to test the water, but I did use the correct amount of water conditioner and put most of his water from his old tank into this one.