Is it in a pot? And where is this located geographically? Marjoram is a Mediterranean native of dry fast training soils which should require no supplemental watering once established in the open ground.

Yes, it is in a pot. Sorry, but I do not know what "located geographically" means.

'Located geographically' means where in the world are you gardening? We have posters from all over the world so unless we know where you are we might be giving totally inappropriate advice.

Pot culture can be problematical. Is it impossible to plant it in the ground?

We live in zone 5. I have already potted my marjoram, and I planted it late May. It was perfect except for the last week.

You say you have been watering it every other day for the last week. and you say it was fine until last week. I think that is your answer.

Ah, thanks! I didn't know that I answered my own question!