I don't think you will lose your mom over this. And, if you do, then she has some work to do on herself, don't you think?

As a daughter, I had to gradually separate from my mom, despite the fear I had (they were/are controlling people). Sometimes it was bad, sometimes it wasn't. My kids separated from me. I try to make it okay for them...(I hope I do, anyway)

I guess my point is that there is no "right" way to be a daughter or a mom because there are no rules and no predictable outcome.

It's scary, but when the time comes to tell her, know that her reaction is probably going to be less than thrilled. But, AND THIS IS THE IMPORTANT BIT: Part of becoming an adult is knowing that YOUR wants are perfectly valid.

Hugs to you...You can do it.