I'm sure you realize this now, but so others can learn from your mistake...
For next time, and any other younger guys reading this, you generally tell the AF the exact date you are going to PCS. Big blue just gives you a general time frame with a few exceptions. You are given reporting instructions for your next base/assignment/TDY enroute and it is up to you to make sure you meet them. If you have a PCS with a TDY enroute, you need to time your departure to arrive at your TDY at the time the reporting instructions give you. For reporting in to your gaining base, a RLTND is just that. But for a TDY, you generally are given an exact day to arrive on and need to plan your travels accordingly.
I don't mean to talk down to you, but I have no idea what your background is and some OTS and one year ROTC guys just don't have exposure to stuff like this.
Overall, probably won't be too costly. Live and learn.