About four weeks ago I interviewed a university (outside the U.S.) for a tenure-track assistant professor position. The head of the department scheduled a meeting with me the next day, gave me a verbal offer and talked about the package. The interview experience was great and the package is great too, but the thing is that they would not process an official letter unless I said I'll take the offer.
I emailed the head and said yes the week after. They quickly responded and cc-ed the staff who'll be working on the paperwork with me. The staff said they will prepare the documents to seek approval from the university. I was very excited and forgot to ask questions such as timeframe and other details. I also declined an interview invite from another university (these two universities are close so I thought it's not appropriate to do the interview).
Now it's been three weeks but I haven't heard anything from them. I emailed the staff yesterday to ask if there are any updates but haven't gotten any responses so far. Now I'm a bit stressed out and start worrying about the offer. Should I email the head if no response from the staff in the next few days?