The reins go with the roof. Conflicts like these are common and healthy (even though they are stressful for the parents, and annoying and "unfair" to the adult child). They are the exact daily annoyances, and parental over-involvement, and privacy issues that SPUR young people to either buck up and get through it if they want to benefit from parental support beyond the age of 18, or to put their foot down and say "this is SO not worth it", and make other arrangements.

If talking to mom isn't getting anywhere or just causing emotional conflict and bickering between the two of you - try a different approach. Put your creative writing skills to use, and present mom with your grievances in a way that focuses on "I messages" (like I need privacy, I need to feel secure, I am concerned that there is a trust issue between us, I would like you to be involved in this and this and this, but not that) - and not "you" messages, which just tend to get people riled up and defensive. Sometimes just changing the delivery can help things move in better directions.