Dear Abby: How can I set healthy boundaries with my best friend without feeling guilty? I have always been supportive and available because I sympathized with her difficult family dynamics during childhood and adulthood. She often talks to me about her problems with family and ever-changing relationships with men, but rarely allows me or others to share their points of view or personal concerns. Saying "no" to her is challenging under any circumstance, and she demands that all focus be on her in social situations.

I love and accept my friend as she is, and I try to give her all the grace I have. I now realize that setting healthy boundaries is the only way I can sustain our friendship. I know this dynamic may put a strain on our relationship, so why do I feel so guilty? – Tested in Northern California

Dear Tested: That's a good question, and one that I can't definitively answer for you. It's possible that like many women, you were raised to believe that if you assert yourself you won't be considered "nice." That's a mistake because as long as you allow this friend to take advantage of you – and that is what she's doing – the more your resentment will build until the relationship becomes one of diminishing returns. So tell this self-centered person as nicely as possible that you are not a therapist, and because her problems persist, she should talk to one.