I feel like such a shitty brother (and person)

I don't know what it is but my little sister just annoys me so much. She'll make noises and do things again and again even after I ask her to stop a bunch of times in the nicest way possible and when she doesn't I get all mad and mean and after I just feel like shit about it. It feels like we just don't get along at all and I want to hang out with her and be there for her but I don't know how to because then she does stuff and it makes me mad and then I react. Like just now she took one of the candies I was gifted for making this one dude a bracelet and she asked if she could have it and when I said no she bolted and threw it. I told her I wouldn't get her anything again (part of the stuff I was gifted I gave to her) and I told her that I wouldn't hang out with her because I just don't feel respected. It's been a few minutes after that and I just feel bad, I feel like I treat her too harshly and yell at her too much. She shoves me and kicks me and instead of ignoring it I over react and shove her back. I feel like shit about it, she's only 10 and I'm being a complete asshole. Sure she's 10 and doesn't do shit for the house and makes messes that I gotta clean up, but all 10 year olds are annoying. She goes into my room and fucks up my stuff too, and when I call her out on it she lies and says she didn't do it even though it's clear she did and it makes me feel like I can't trust her. It's like once she says the truth I can't believe her and then I get mad at her for lying even if it is the truth, just because she's lied so much. I should be the one she's able to tell the truth too, I should be the one she goes to and can trust, I should spend time with her and stuff but I just get so angry and annoyed at her. She mocks me too, and it just pisses me off a lot. I stim sometimes when I'm stressed or excited about something and she'll copy me with a dumb look on her face and mock me, and I know she's 10 but it just makes me so, so mad. It makes me feel like shit, and then I get mad at her, and it makes me feel like even more shit. I've said some very hurtful things to her that I regret, and I don't know how to stop being such a shitty brother.