This is very much better than your first effort from yesterday. The change in your thesis statement makes the thesis fit much better with the rest of the essay. I only have a few very minor suggestions to this revised version of your introduction.
First, I would add the words “during their time in Australia” to the end of your paragraph just to be clear about where that daunting experience played out.
Second, you should decide whether “South Sea Islanders” and “Islanders” is going to be capitalized. In yesterday’s version, you typically capitalized this. Here, it’s capitalized once but not the second time.
Overall, however, very much better.