I would encourage you to get professional legal help rather than try to continue the process on your own.
While it’s unfortunate that you hired a freelancer that was less than honest, you can go ahead and remedy the situation by getting an attorney on your side. He or She will be able to help you with the issues associated with a stolen idea as well as finish your patent application.
If you are interested in being connected with a patent attorney, check out our website at. We can put you in touch with a qualified, professional lawyer that can guide you in the right direction. Best of luck to you!