Hi, AryaSnow, and welcome to bpdfamily!
I have a mother with BPD and understand a lot of what you are feeling. It's great that you are already getting some professional support--I found that tremendously helpful. The peer support here is also pretty outstanding. If you haven't already, you can start checking out the LESSONS at the top of the board. There are some great ones in there about boundaries and enmeshment. We also have a handy Survivor's Guide over on the right that outlines what the recovery process might look like (it's not necessarily linear).
One great thing is that our ability to heal and grow isn't dependent on whether the other people in our lives have a diagnosis, and how we see ourselves doesn't have to depend on how the other people in the lives see us. Could your SIL have BPD? Sure, it's possible. And if so, that could possibly help you understand how she sees the world and why she acts the way she does. In the end, though, I think what's more important is how you decide to respond to the behaviors you find troubling. Could your mother or SIL take offense to your boundaries or misinterpret your intentions? Absolutely--in fact, very likely if they have BPD. Ultimately, though, you don't have to convince everyone else to agree that you have a right to take care of your own feelings--you get to decide how you feel about yourself and your choices.
The biggest problem I face for both my mother and my SIL is that they constantly demand to know why I am not telling them how I feel when they can tell I am being distant. I have no idea what to say when I am thinking that they have uBPD and that their actions are selfish and worrisome because I know all too well that I will be punished for expressing myself or saying something they do not like.
What does your therapist suggest? What would it feel like to say, "I don't want to share my feelings with you," or "I'm not comfortable discussing that with you," and then end the interaction if they continue to make you feel pressured? It's not necessary to explain why you need a boundary or tell someone
why you don't want to talk about something--it's enough to just decide you're not going to. Justifying, Arguing, Defending, and Explaining (JADE) your choices can contribute to staying stuck in a cycle of conflict. It does not make you a bad or "cold" person that you don't want to share your feelings with people you don't trust. You mention that you fear their punishment and retaliation. What does that look like in your family? In your husband's?
You also ask:
My plan is to work very hard and consistently with my SIL to enforce boundaries, but after working hard to try to figure out my relationship with my mother, to again find another conflict with a BPD in my SIL makes me feel like I attract these sorts of people to me and makes it hard not to blame myself for our conflicts. Have other children of BPD parents found themselves in similar situations? How can you extract yourself after you realize you have let your guard down? And would it be advisable to tell my SIL that she reminds me of my mom who I suspect has uBPD?
Many children of BPD parents do find that we choose relationships with people who let us continue in comfortable roles (such as rescuer). Since we didn't learn healthy boundaries as children, we tend to allow all kinds of unhealthy behaviors from others and worry more about hurting someone else's feelings than taking care of our own. That does invite dysfunction into our relationships. It sounds like this SIL is your husband's sister (rather than, say, your brother's wife)--is that correct? Perhaps one of the reasons you and your husband connected with one another is because you both grew up in an environment with this kind of personality. Have you talked about your mother's BPD with your husband? How much does he already understand? Has he ever talked to a therapist on his own?
To address your last question in that quote, my observation is that it is usually not very productive to tell someone you think they have BPD. First of all, that's really best left to the professionals, and secondly, you can imagine it is not an observation that other people tend to receive well. It is not likely to make her go, "Oh, gee!
No wonder I have so much conflict in my life, I'd better get myself some help." So while you might find some comfort talking about the possibility with your husband, you might not find it as helpful to try telling her.
In my life, I find that if I am feeling really angry or resentful toward someone, it is usually because I have not been taking care of my boundaries. I feel better when I say no to things I don't want to do, for example. I have also had to learn to allow myself to have my own feelings--you can feel what you feel even if other people feel something else. I can have different boundaries than my husband does, too... .we are both adults and we can respect each other's differences. For example, sometimes I might say "Hey, I think I'll skip this family function. You can go without me if you want to." What would that feel like in your situation?
Wishing you peace,
PF
