我这是在干吗？英文怎么说？

What did I do,或者
What I have done
因为这句子里有一种后悔的味道，所以用过去时或者是完成时较恰当。
希望对楼主有帮助。

What am I doing?
What on earth am I doing?
实际上在这种情况下很少有人用过去完成式的, 外国人脑子转不过那么多弯的

What the hell am i doing?
What have I done?
What am I doing?
What is this am I doing?
What did I do?