Jennifer,
I am also self-employed and I have very tight NDAs with every client. For projects that I listed on my PMP Application, I requested from each client, in writing, if I could use their company name and my technical contact at the company. All but one said "yes" and on that one, I said, "Confidential Client - Petrochemical Industry" and gave a very vague project name and all of the other information. PMI accepted that.
Harry