AITA for refusing to work things out with my fiancé because my life is better now that his daughter isnt around me?

I know the title makes me look like an AH. I accepted that. But, for full transparency, I wanted to be completely honest here.
Basically, I had been with my fiancĂ©, Matt, for 8 years. He has a daughter, 14yo “Vivian”. I tried so hard to involve Vivian in everything. I enrolled her in all of these extra curricular programs and showed up to every single event. I spent thousands on things she wanted/needed. I brought her out for one on one to do girly things like get our hair and nails done or even go shopping. One on one dinners wherever she wanted to eat. She literally complained about everything. Every time I brought her out to eat, she complained loudly about the food being trash. Every single time we went and did our hair and nails, she would complain that it turned out bad. Complained on Christmas and asked if she “had more stuff coming” because she only had 16 items under the tree (literally everything on her wishlist) and she “was grateful but disappointed because she expected more from us”.
Tie this in with other things.. like all my stuff going missing constantly. My make up, that she had been told not to touch several times, became free game for her. My hair brush, that I also told her not to touch, was always left on the counter with giant chunks of her hair left in it. All her hair products and make up sit right beside mine in the bathroom and despite her stuff being higher quality, she still uses mine. Literally spaced out whenever I tried talking to her about it. Her eyes would just gloss over and she would stare right through me, nod her head and say “mhmm” or tell me why it wasnt a big deal and she was tired of me creating drama with her. My clothing? Yeah half that shit is missing and I would catch her wearing them and she would blatantly lie and gaslight me by saying “you literally gave me this and now you’re going to flip out”. She just had zero respect for me and that was obvious. Her dad did absolutely step in every single time and reprimand her but it never got better.
It all came to a head over a damn bowl of tuna. So, my fiancé and I have a 2yo and she has been extremely ill. I am so busy dealing with fussiness all day and seemingly all night long that I simply forget to feed myself. So, 3 days ago I get the baby to sleep and go lounge in the livingroom and start making myself some tuna for crackers around 11pm. Vivian comes out and sees me making it. She gets herself a drink and goes back to her room. The baby wakes up so I put my tuna in the fridge. Get the baby back to sleep and when I come out, Vivian is on the couch eating it. It was the last of the tuna and I was starving and really craving it. I didnt eat dinner because I didnt like the meal I made for Vivian and Matt. So, I snapped a bit. I asked why she would be touching my food when she already ate dinner and she really just rolled her eyes, tossed my bowl kn the counter and slammed off to her bedroom. I immediately woke up Matt and told him I was done. Him and his daughter needed to get out of my house by the following day and go stay elsewhere.
Anywho, he went to his moms with Vivian and holy F has my house been peaceful since they left. Matt keeps asking if he can “come home” and talk but I told him I honestly just dont know if I want to work this out because my life has been nothing but peaceful without Vivian here. He keeps saying things like “you dont mean that, you love her, you’ve been around for more than half her life” but I really, truly have come to the conclusion that I do not like that girl and I love my life now that shes not a part of it. AITA for throwing away 8 years and a very loving relationship over his kid?