I can understand both sides of the issue, yours and your mom's. I had a mother who did to me just what you've described your mom doing to you. I was also the youngest child by many years. The difference was that my parents were divorced. Also, I fought my mom about having outside friends so that even though she wanted me to spend all of my time aside from school with her, I refused.

I was married at 18...my mom still expected me to spend a lot of time with her. I mean, A LOT of time. She pretty much did all she could to weaken my marriage (saying crap to me about my husband, telling him crap about me). Really, she wanted me to live with her...that would have been her preference.

All along, I set my own limits. I spent plenty of time with my mom, but I also spent the bulk of my time with my husband, my children, and my friends. My mom never was able or willing to make friends for herself, which was unfortunate because she was a charming and interesting person and could easily have had friends of her own. But she flatly refused.

When my daughter was about 4 my mom started trying to somewhat replace me with my daughter. I allowed my daughter to spend lots of time with "Gram", but I put limits on that, too.

By the time I was 40 and my daughter and son were teens, my mom felt very neglected. She spent the last couple of years of her life feeling very bitter and terribly lonely. She died a terribly sad woman. It was pitiful.

Now that my children are grown and living their wonderful lives I wish my mom was alive, because now I would have a lot of time for her. But, things didn't go that way.

I think it's wonderful to be best friends with your mom. That said, my suggestion to you is to set healthy boundaries- set a limit on how much time (including phone time) you give to your mom. And do not engage with her abusive commentary about you. I hope you can remain dear friends with your mom while setting limits with her.