How do I get personal accounts of contemporary adult mother-son incest or adult mother-son sexual attraction for a confidential research project?
I'm not sure that you are going to get any personal answers to this question on eNotes, however, this topic is not so esoteric that you won't be able to find anything. If your level and field of study require field work, the best first step is to ask you instructor or adviser how to put out a call for volunteer subjects. Any call would include a statement of extent of use and of confidentiality.
In addition you might use an academic search database. If nothing else, Google Scholar is a great place to start, otherwise your college or local library should permit you free access to the database they subscribe to like "Academic Search Premier."
The topic you have listed is actually a psychological term known as the "Oedipus Complex." For background information, you might start there for a keyword search. I think you could also find some published court cases (which would include personal accounts/testimony in the abstract) about your topic.
Any journal articles written and published by psychologists or doctors about this topic provide sound background information and case studies with personal testimonies. Remember, also, when searching for scholarly journals, the keyword search begins as a bit of a hit-or-miss endeavor until you find one or two things you can use. Then, let these sources provide you with keywords or names for further searches.