Jazzy, I absolutely see the contradiction.

And I don't mean to sound like it's an easy process at all. However, the healthiest way to deal with boundary violations is through communication. Again, don't take this to mean "go out and communicate what you feel right away." Not at all! Like I said before, start by journaling about your feelings. Or you can even discuss them here! But something to help you identify what those feelings really are, and what might be causing those feelings.
May times it's helpful to identify what automatic thoughts we have that lead to our feelings as well. Sometimes we can gain greater insight to ways we can affect our own emotions.
But only after truly discovering and becoming comfortable with the emotions you experience do you want to try communicating them. So I'm not saying you should communicate your feelings because as you said, that's difficult. Instead I'm saying take your time, become aware of your feelings, take the time to take care of yourself in those emotions, find healthy ways to express them (privately even), and once you're comfortable and ready you can communicate yourself and place healthy boundaries.
Does that make more sense? I know that it's still saying to share your feelings when you don't want to, but at the same time your family member wants to help you but only hurts you in her attempts. The only way to take care of yourself in a healthy way is to set those boundaries through communication.
I know that isn't easy, and I know that it may be very uncomfortable, but that's why you have support here through us. Let us know what you need.