Hi! I think you can say "Estoy enganchado a esta canción". it's like "Soy adicto a esta cancion" but don`t sound negative.

I will say: "Me encanta esta canción" or "Me vuelve loco/loca esta canción". It is more common this sentences than "Yo estoy/soy adicto a esta canción"

Hello ! "be addicted" = " ser adicto " However, in many Spanish-speaking countries the word "addiction" it's a little bit negative. I think you can use the word " fan" or " fanático" ( "fanatic") to express the same idea. " Soy fanático/a DE esta canción " ( "fanatic OF " ) " Soy adicto/a A esa canción " ( "addicted TO " ) Best wishes Sofía.

Literally it is "Soy adicto a esta canción"(if you are a man) or "Soy adicta a esta canción" (if you are a woman), but you can also say "Me encanta esta canción".

Also how to say " I have this song stuck in my head"?