Hello my name is ***** ***** I am going to help you today. I am a NSW solicitor.
What you first need to do is to establish which company or entity has made representations to you that you have relied upon to your detriment. If the company is Australian and has assets in Australia (which you can check through doing a credit, property and annual report check) then you should sue them in Australia for negligent misrepresentation or breach of the Australian Consumer Law. Which one is best to sue under is not immediately apparent to me without all of the facts and further research that needs to be done. But you will need to make a comprehensive list from your memory, diary and emails and other evidence of what representations were made to you about the property and when and how (i.e. who verbally said them or what advertisement did you see that stated them). Your representations will be, for eg., "that the residential property I purchased at 10 Lowy Place Utah was worth $1 million and would likely increase in value by 10% over 5 years" or something. You need to be specific about what was represented to you and what failed to materialise or be realised. Gather written and pictorial evidence about how and why the representations failed to become true. Consider whether you totally relied on the representations or whether other factors came into play that you also partly relied upon and record this. Then go and get some advice from a lawyer about the prospects of success of your claim. That is something beyond the scope of this website as we only give general advice. You don't have to feel trapped, you can take action on this.
If the company is a company in the USA and has assets in the USA, you are best to speak to a United States lawyer in the State of where you are either living, where the company is or where the properties are situated. Those lawyers should be able to advise you on the laws of the State in particular and whether other State laws will have an impact on your claim. I do not know whether they have a similar law in the United States for negligent misrepresentation or breach of a consumer law. However another possibility is that you obtain a judgement in Australia against the company and have it registered in a Court in the State of the United States where you will get the best outcome of enforcement. Again, a United States State lawyer can help you with that.
I wish you all the best and hope that you are able to secure a favourable outcome. If you carry out the first exercises I have described, you can test for yourself the strength of the evidence you have to mount against the company and how much the value of your losses are.
I hope I have helped you today. If so, please rate me positively. All the best.