～、。
Oww... I went and goofed up again, didn't I.
Literal
Ow, I [exasperated-ったら] again blundered-[casual しまう-ちゃいました].
The interjection あう~ is the anime-style cry for 'ow' or a sheepish cringing sound. あたしったら is the speaker referring to herself with the exasperated topic particle ったら ('myself, really...'), a colloquial form expressing self-directed exasperation — parents commonly use it on children too (e.g. 太郎ったら). ドジる is a colloquial verb derived from the noun ドジ (a blunder, slip-up) using the productive ~る verb-making suffix. ~ちゃいました is the casual contraction of ~てしまいました, with the ~てしまう adding a nuance of 'went and did it, unfortunately'.