The sentence in the paragraph that is structured differently from the others is [2] "He faced insults and difficulties doing this; however, he was determined to continue making money, which he did".
In the second sentence, "however" is joining two independent clauses ("He faced insults and difficulties doing this" and "he was determined to continue making money, which he did"), which means that it is connecting two clauses that can stand alone. At the same time, the second clause contains an independent clause and a dependent clause ("which he did"). Therefore, this sentence is structured differently from the other sentences, which are only made up of one independent clause and one dependent clause.