It could take a long time to re-phrase these sentences in different words, which you may not understand either. Could you give us your guess for each one and we can try to correct you?

1. I am always studying, flipping through my index cards while I walk around the city. Index cards are small cards that have little notes to help you remember and is a tool used for studying. The speaker is saying that he/she is always studying even when walking around the city. 2. Where am I getting the brain space to store these words? This is a rhetorical question (a figure of speech) that's not meant to be taken literally (there's no answer to the question, it is supposed to get a message/idea across) If I were to rephrase it, the speaker is saying "How am I supposed to remember all these new words?" 3. I am exhausted by the cumulative consequences of a life time of nasty choices and chaotic passions It roughly states that the speaker is tired of the consequences (the bad outcome/result) that was growing because of the bad choices they made in life.