There's a backstory to this relationship that I must first tell, because it gives context to my current feelings of hurt and resentment towards my sister. Please bare with me... this is long, so thank you for reading it all the way through!

While going through her own divorce years ago, my sister used me and hurt me very badly.

She snuck around behind her husband's back to sleep with the landscaper, and used me as a cover the whole entire time, for months and months.

She would always tell me that she wanted to come visit me for quality time with me, but then in reality, she would arrive at my place, then use my phone to call the landscaper, and would meet up with him instead!

She did this numerous times and in a variety of ways. For example, one time, she pretended she wanted to celebrate my bday with me (a month early), so she invited me for a pedicure in the city, and then it turned out in reality she had planned to meet up with the landscaper. So, it was all a HUGE lie and cover up, once again. There is much more to the story, like how she would also invite me out for drinks at a bar, but really, she just wanted to meet & screw other men.

So, this ended in a huge blowout fight whereby I told her off after enduring months of this behavior. The fight occurred while she was visiting me in NM, once again, under the guise of wanting to spend quality time with me, when in reality she had ulterior motives. Also, while visiting me in NM, I had shown her a photo of a guy I had a HUGE crush on. I told her I had a crush on him, and her response? She said to me, "I want to meet him. Can I kiss him? I want to kiss him!" I was astounded and hurt by this comment.

I was SO deeply hurt by her treatment of me for all those months, I eventually forgave her, but never forgot what she had done to me. She never even apologized, even after I had told her how much she hurt me.

So, here's what JUST happened NOW:

I had asked her to come feed my cat while I am away for 3 days. I asked her to only come once on Sunday to give her fresh wet food. Originally, my sister said she could do this for me, as long as she doesn't spend the night with her fiance. I figured she would find a way to work it out and do me this one small favor. I never ask her for anything, and I had no one else to ask.

Well, then she tells me no, I can't do it and I am spending the night with my fiance. Since I have no one else to ask & am desperate for help, I got mad. Granted, I know I did not have a right to get so angry, but I got angry because I figured that I had done plenty of favors for her, that she could do this one favor for me.

So, over text, I got mad and said that she doesn't care about me or mom. I mentioned how she doesn't ever come to Thanksgiving dinner with us, even just after our father died. She spent Thanksgiving alone with her fiance, and me and mom had to spend Thanksgiving just the two of us. That was our first holiday without our dad. I then told her she isn't a part of the family. I said this out of anger because she wasn't willing to help me.

Well, so I said that and her response to me was: "F-YOU AND YOUR F-ING CAT!!! YOU ARE A SELF ABSORBED PSYCHO F-ING BIT*CH!!!!" Her exact words, and all in caps. This was all said by text.

So, I told her I am NOT speaking with her ever again, that I am disowning her, I blocked her, and unfriended her. I told her 3 adult sons, my nephews, in a group chat that I am disowning her, I shared her words with them, and told them I will NEVER forgive her for this .

She tried to apologize, but my blood was boiling and I was severely triggered by her cruel words that cut me like a knife, and by all the past hurt that came back up to the surface for me.

Now, mom is aware and refuses to allow a rift between family members to exist, and is insisting upon mediation between my sister and I. This mediation meeting is tomorrow, the anniversary of my father's death. Mom wants to lay down some ground rules.

However, I am SO deeply hurt and disturbed by her heinous words to me, that I believe there is no getting past this incident and that I will not wish to speak to my sister anymore, if at all. I cannot imagine us truly being able to move on.

Underneath ALL. of this is the fact that my sister (I believe) resents and hates me because she told me more than once she believes that mom never loved her, and that she only loves me. She felt this way as a kid growing up. So, that's underneath everything else. I think she only pretends on the surface to care about me, when deep down, she actually hates me. And, it isn't even my fault... but I believe she resents me because of our mother, and I believe this is why she treats me the way she does.

I know I was in the wrong with the things I said to my sister, especially saying that she is not a part of the family. I know this was wrong & hurtful of me to say, and it is why my sister lashed out at me in response. I also know I should not have mentioned this to my nephews, her 3 sons.

I will apologize to her, and I expect an apology in return, but I'm afraid there's just too much damage done within this relationship historically for me to ever really feel close to her again. I will certainly never confide in her again.

The whole thing is very upsetting. We are the only siblings, our mom is 81 years old and when she leaves us, it will just be my sister and I left. And when my mother is gone, I fear that my sister will not be there for me, if I need her. I'm afraid that she will be passive aggressive towards me, as she always is towards everyone, and always has been.

This all pains me so very deeply because she is my only sibling, and we have a ruptured and dysfunctional relationship.

What's even worse, is that after my mother is gone, my sister is in charge of doling out my inheritance to me, along with my cousin, in case I have mental health issues as an older adult. I may have to talk to mom about changing this to be only my cousin.

I'm looking for supportive, kind, and compassionate replies only. Please be gentle with me. I have been through SO much in the last year & am very fragile. I have acknowledged and own up to where I went wrong.