Has this been approved by your teacher yet? I would say that your hypothesis doesn't reflect your question as well as it perhaps should. For instance:
Statement: An investigation into the impact that maladaptive perfectionism has upon the wellbeing of senior high school aged adolescents., Question: How does maladaptive perfectionism influence the state of wellbeing experienced by senior high school aged adolescents?, Hypothesis: Maladaptive perfectionism has a negative impact upon the state of wellbeing experienced by senior high school aged adolescents.
I think you should be slightly more specific in your question (eg:
How do alternate variants of stress (-- you can talk about external and internal pressures within the HSC such as self inflicted stress, stresses from family, a want to do well/achieve particular marks, pressure of the media/general society; this will also give you a larger spectrum of potential questions as well as who you can conduct your research methodologies on (remember you're not just limited to students... you can interview ex-HSC students for a reflective opinion/parents of students who are/have undertook the HSC) as well as your secondary research--)
inflicted upon year 12 students by the HSC affect holistic and individual wellbeing?) -
then your hypothesis will make a lot more sense (i.e. stating that the majority of stress is created perhaps unnecessarily by students themselves).
_____________
Coming back to your original question, if you conduct your 'structured questionnaires' (remember your terminology for maximum marks) through Survey Monkey, you can distribute them via the boredofstudies forum
here, and I'm sure everyone would be happy to help you out - just remember to thank both Survey Monkey and the bos forum for their services in your aknowlegements.
You also want to make sure that you can get enough reputable secondary research for your literature review - and absolutely make sure to print out and highlight ANYTHING that you find and put it into your appendix whether you quote from it or not. Trust me, the last thing you need is to be accused of plagiarism and be completely stripped of your marks, because yes, it does happen even to the most well meaning of people.
If you need anymore help, feel free to message me. I really enjoyed the IRP assignment, strangely enough.