For this reason, I am looking for a lawyer who can work on a pure contingency-fee (no win, no fee) basis so that I do not have to pay any upfront costs.
Well-known law firms and support organizations that come up on the internet, including SBGOK, have already declined my case, and I am in a very difficult situation.
That's not going to work; it's like working pro bono, and this is a gambling case where your chances aren't good unless you present a strong case. An intermediary has victimized you because he knows you have a weak case, and he exploits it.
You are opening yourself to getting victimized again because those who will contact you will make you believe that you have a winnable case, and they will entice or even force you to send them money.
You should move on and start your life away from gambling. You have a great life ahead of you.