Learn Spanish (Latin America): Estoy cada vez más desorientado por este arbusto interminable. - I am more and more disoriented because of this endless bush.

In this sentence, por means because of or due to. We use por followed by a noun phrase (este arbusto interminable) to show the cause of the speaker's confusion. You can't use porque here because porque must be followed by a full clause with a conjugated verb, rather than just a noun.

How does cada vez más mean more and more?

The phrase cada vez literally translates to each time. When you add más (more), the set phrase cada vez más becomes the standard Spanish way to express more and more or increasingly.

Would a female speaker need to change the word desorientado?

Yes, because desorientado (disoriented) is an adjective describing the speaker. A female speaker would change the ending to match her gender, saying Estoy cada vez más desorientada.

How is the word interminable formed?

It means endless or never-ending, and it is built from the verb terminar (to end or finish). By adding the prefix in- (not) and the suffix -able (able to be), it creates a word that literally translates to not able to be finished.