Stop touching him, this is only causing him stress. Taking him out of the water is also causing stress. Try to get it upright if possible but then leave him alone. If it had been dead then you would have known by the smell when you took him out of the water, or he simply would have disintigrated in your hand while still in the tank. These are (especially the sebae) delicate animals. A dead anemone will look like a blob of melting ice cream. Yours isn't dead.
Is someone going to watch, feed and top off, your tank while you are away?
First two weeks are critical and he will be acclimating himself in many ways to your tank. Try to feed him before you go on your trip.
Can you post a pic of yours?
Thomas