my sister's relationship triggers me

[something636]

So my sister is in her late teens and I'm in my early twenties, when I was about her age I was in a somewhat toxic relationship for a good amount of years. It was my first love, so it started off innocent and sweet and only grew worse over time, eventually having a really bad ending which has left me with my own traumas. It's been a few years now, I am completely over him but still trying to heal and uncover parts of myself as you do when you're in your twenties. I've dated since then, but mostly remained single and still am, by choice, as I feel I still have much more maturing, therapy, self-discovery/development, etc to do. However, my sister is pretty much going through the exact same thing I was at the time, in a "toxic" relationship which she doesn't seem to realise (and I never did until mine ended), and I fear her relationship too will end badly. I've already had this discussion with her but she's decided I'm not supportive and since then, no longer shares anything about her boyfriend or even personal life with me (her only friend is him so she doesn't have much else of a personal life), which hurts as we used to be extremely close, and I never used to hide anything from her.

I know the right thing to do now probably is to be supportive and let her learn from her own mistakes, but I can't pretend to support a relationship when I don't. This relationship has really changed her, for the worse, and she's become difficult to be around. There are just certain behaviours she does that I can spot from a mile away and I see my old self in, which looking back now, after some years, it's as if I was looking at my old self and I just wish I could shake her and tell her to stop. But I've just kept silent for a few years now. It's hard because I get triggered and then I have to deal with it for however many hours or even days afterwards.
I want to just feel free, and stop focusing on her life and focus on my own. I want to stop caring about her. It hurts way too much. And there's truly not much I can do, I've spoken to her already but she's extremely stubborn, defensive,... Like I said, she's changed for the worse... and so far I've just been telling myself all I can do is wait, but I'm realising now how much I'm slowly breaking as I wait. She triggers me, I get anxious, she looks down on me and thinks I'm jealous just because I'm single and she isn't, she gets validated by him and him only, everything she does/buys/wears/eats/posts anything is all for him and his approval, they text/call 24/7, even if they've spent an entire day and night together she'll come back home just to continue texting him/ I am working and saving to move out of the family home so I don't get triggered so much, but this realistically will take me a number of years and it's not so easy. In the mean time, I just want to stop caring about her overall but I don't know how to let go of this overall. Our relationship just isn't the same, some days there are good days when she hasn't met him in a while, she almost returns back to her usual self, but once they meet she turns back into this person who is impossible to be around.
What can I do now to move forward?
How can I stop caring so much?
How can I heal and not get triggered?
Basically, since she won't change... what can I DO to change myself in this situation?
I don't even know if I've asked the right questions, all thoughts opinions and answers are welcome... I'm just sick of living in this same situation day to day.
Thank you for reading.

 

[OrangesandCashews]

I think you’ve done all you can. You can’t really stop caring about this or your sister, but offering her your support maybe giving her your phone number. I think just letting her know you’re there and maybe sitting down to talk to her about it. Just saying you’re there for her and that no matter what she can reach out to you.
Your fear and frustration is valid it’s coming from such a place of hurt.
I think the best thing you can do for yourself is be there for her but doing things that are good for you. That remind you of your “safe place” in the world even if that’s staying with a friend on the weekends or going out to hang out with friends more often, or hell watching video essays on YouTube. I think whatever you do for self soothing is good. You can’t ever really stop caring but what you can do is also show that same amount of care and worry to yourself and apply what you know already from yourself.
I think I’m time your sister will come around. Just be sure to never give her the “I told you so” response and just be open and there for her if/when she does.
When you also talk to her you can tell her about your past experiences you’re comfortable with sharing. You aren’t alone in this journey and you deserve the same amount of love, respect and happiness you have given and the worry to after the relationship you’ve gone through.

 

[Friday]

If you’re triggered? That means you’re overreacting. By definition.

So you’ll need to sort out what is totally legitimate concern, legitimate action… and what is bullshit PTSD freaking out & overreacting / underreacting.

 

[Movingforward10]

What can I do now to move forward?
How can I stop caring so much?
How can I heal and not get triggered?

It's tough, but take a step back.

No one likes being told what to do. She has the right to make the relationship she wants. Whether it's abusive or not? You have your worries, but like Friday says: working out what is you bringing your stuff and what is your genuine worry for her.
Even with genuine worry for someone: can't stop bad thing happening. All you can do is be there. Hope she opens up to you so when she's ready, you're there with your understanding.

Triggers: recognising them. Thought stopping. Grounding. Etc.