Not that I mean to defend the prequels too much, but to be fair, by the point he force-chokes her, he has turned to the dark side. Who's to say what the influence that the dark side would have on someone, especially someone as emotional as Anakin was before he turned. I would think that he would be extremely emotional and unpredictable after turning and very prone to violent outbursts that he would later regret, such as killing Padme. So I don't see the inconsistency here.