Luana You are doing great!!
I know what you mean with the breathing while swimming.
I have to do most of my swimming on my back & in the beginning when I did a length I stood at the end & heaved for breath for ages.
3 yrs down the track I can swim a length over arm & just take a few seconds to get my breath back ---but I still can' t manage a full 2 lengths over arm without running out of puff.
I can now swim 1km on my back in 35 to 40mins. Oh that's with flippers on.
Good for the thighs flippers.
I have a bathing suit with a big skirt on it ---looks like an old style tennis dress