coming or going

not know if /whether one is coming or going and not to know what to do for the best (be in a state of mental confusion; feel very confused, usually because you have too many things to deal with) — растеряться; не знать, что делать; не знать, на каком свете находишься; ~ совсем потерять голову (от растерянности)

Example 1: I’m so tired, I don’t know whether I’m coming or going.

Example 2: I've got so much work on my desk. I'm really confused. I don't know whether I'm coming or going. — ... просто не знаю, за что и браться, голова кругом идет

Example 3: You look a bit harassed. Is everything all right?— To tell you the truth, I don't know whether I'm coming or going.

Example 4: He has so much to do that he doesn't know if he's coming or going.(The American Heritage Dictionary of Idioms)

also
not to know which way to turn

Example 1: It's not too much trouble, mother. I'll tell you tonight, " I said not knowing which way to turn. (C. S.)

Example 2: Oh, this is awful — I don't know what to do nor which way to turn! (M. T.)

not to know if one is standing on one's head or one's heels