How's my spanish?
Your Spanish is nearly perfect.
It isn’t easy to realize you are not a native speaker of Spanish.
There are only a few mistakes:

“He realizado…” - - > “Me he dado cuenta…”
“Nuestro mundo está llena de…” - - > “Nuestro mundo está lleno de…”
“Peleando de nada” - - > “Peleando por nada”
Esta tema” - - > “Este tema”
“Muchas gracias por ver y…” - - > “Muchas gracias por verme / ver este vídeo y…”

But these mistakes are not important: everybody can catch your message easily.
And, yes, you are right: we often give great importance to little things but forget the really important ones.