i'm 100% sure that anakin's confession was at least partly an attempt to push padme away, especially considering that anakin started talking about the massacre after padme had already begun to sympathize with him, as if it was a response to her compassion. i think he expected her to scold him and confirm his negative self-image. after anakin finishes talking about what he did, he sinks to the floor, and there's a brief moment where padme takes a few seconds to process what she heard, and anakin glances at her periodically. the way he turns his head toward her and jerks it back while shaking could indeed suggest that he thought she would turn away from him after the confession, but was afraid to face it
honestly, i think hayden christensen played that scene really well, but a lot of people don't pay attention to how anakin talked about what he did, only to what he did. i know g-lucas specifically asked the actors to give slightly exaggerated performances because he wanted to make sw 'basically silent movies', which is why the dialogue can seem a little wooden or unrealistic, as the films can be experienced entirely without it. like, if you watch this scene in a language you don't understand, you can see how anakin's emotions, his facial expressions, and his body language change — even without dialogue, you can still get the basic idea, which is 'anakin did something really bad and it scared him and he confesses it to padme, who calms him down'. i mean, he starts with grief and guilt, and then, trying to rationalize what happened, he moves to anger ('it's all obi-wan's fault'), but when he gives in to anger, it scares him: he looks at his hands in shock, you see how he is shaking, how he looks around, trying to fully comprehend what he did (in the script, g-lucas writes "anakin focuses on her like someone returning from far away", which suggests that he is still dissociating), and only then does he begin to talk about what he did, and he starts sobbing right after that — this scene conveys so much guilt, regret, self-fear and self-hate :/
and then i go online, and see people post that anakin didn't regret the massacre at all and was racist and padme 'should have dumped that maniac who bragged about committing mass murder' and red flags and all that, and i'm like. bro.