No worries. In the future (i.e any thing for the K-1 visa the consulate uses, I-485 packet, I-751, and N-400), use DHL next day service. This way it goes directly to the DoS/USCIS facility. Always send on a Monday that is not a federal holiday so that it arrives before Saturday and you are not stressing over it sitting outside the office all weekend.
That is too bad, because I-129F was the simplest part of the process. I-129F was not the better choice for someone who is prone to stress. Also I-130 can be filed online.