It really follows the basic song structure, verse, chorus, verse, chorus, bridge, chorus, etc. Just that the way it repeats it is hard to tell, and does not feel that way.
The verses basically are three words, repeated with three added on. For example,
Find a cure
Find a cure for my life
starts the song off, repeating that four times. The chorus is similar in style, but slightly more lengthy.
There are two bridges of sorts, if they can be called that. The first one includes the album title, Fortress Round My Heart, as there is no title track, and the next one is a sentence in the form of a question that relates to the chorus.
All in all, it makes the whole song feel like a chorus, and definitely a good listen, and a nice way to start the album.