Congratulations for your idea, Sofia!
I second everything Jespah and Farmerman have said about help from lawyers. In addition to that, I'd suggest that you browse some patent databases to see just how new your invention really is. If it isn't, it's better to be disappointed now rather than after you've invested time and money in the patenting.
Here is a page with online patent databases
. It will depend on your field which one is best suited for your needs. For what it's worth, at my own employer (multinational, IT/electronics), we have made good experiences with the IBM patent server, and we use it by default.
I think one of the "jobs" of a patent atty is to do a feasability study--to see if it has a market-- The kind of stuff I can't do by myself.
I'm not sure if that's the case in America, but it isn't in Germany. A patent attorney's job is to look if your idea is patentable and write the broadest patent application that won't infringe on other people's patents. Feasibility studies and profitability studies are not the domain of the patent lawyer, as they deal with problems of engineering and marketing, not law.